pageserver: remove legacy attach/detach APIs from swagger (#6883)

## Problem

Since the location config API was added, the attach and detach endpoints
are deprecated. Hiding them from consumers of the swagger definition is
a precursor to removing them

Neon's cloud no longer uses this api since
https://github.com/neondatabase/cloud/pull/10538

Fully removing the APIs will implicitly make use of generation numbers
mandatory, and should happen alongside
https://github.com/neondatabase/neon/issues/5388, which will happen once
we're happy that the storage controller is ready for prime time.

## Summary of changes

- Remove /attach and /detach from pageserver's swagger file

pageserver/src/http/openapi_spec.yml

@@ -567,114 +567,6 @@ paths:
             application/json:
               schema:
                 $ref: "#/components/schemas/ServiceUnavailableError"
-
-  /v1/tenant/{tenant_id}/attach:
-    parameters:
-      - name: tenant_id
-        in: path
-        required: true
-        schema:
-          type: string
-    post:
-      description: |
-        Schedules attach operation to happen in the background for the given tenant.
-        As soon as the caller sends this request, it must assume the pageserver
-        starts writing to the tenant's S3 state unless it receives one of the
-        distinguished errors below that state otherwise.
-
-        If a client receives a not-distinguished response, e.g., a network timeout,
-        it MUST retry the /attach request and poll again for the tenant's
-        attachment status.
-
-        After the client has received a 202, it MUST poll the tenant's
-        attachment status (field `attachment_status`) to reach state `attached`.
-        If the `attachment_status` is missing, the client MUST retry the `/attach`
-        request (goto previous paragraph). This is a robustness measure in case the tenant
-        status endpoint is buggy, but the attach operation is ongoing.
-
-        There is no way to cancel an in-flight request.
-
-        In any case, the client
-        * MUST NOT ASSUME that the /attach request has been lost in the network,
-        * MUST NOT ASSUME that the request has been lost, based on the observation
-          that a subsequent tenant status request returns 404. The request may
-          still be in flight. It must be retried.
-
-        The client SHOULD supply a `TenantConfig` for the tenant in the request body.
-        Settings specified in the config override the pageserver's defaults.
-        It is guaranteed that the config settings are applied before the pageserver
-        starts operating on the tenant. E.g., if the config specifies a specific
-        PITR interval for a tenant, then that setting will be in effect before the
-        pageserver starts the garbage collection loop. This enables a client to
-        guarantee a specific PITR setting across detach/attach cycles.
-        The pageserver will reject the request if it cannot parse the config, or
-        if there are any unknown fields in it.
-
-        If the client does not supply a config, the pageserver will use its defaults.
-        This behavior is deprecated: https://github.com/neondatabase/neon/issues/4282
-      requestBody:
-        required: false
-        content:
-          application/json:
-            schema:
-              $ref: "#/components/schemas/TenantAttachRequest"
-      responses:
-        "202":
-          description: Tenant attaching scheduled
-        "400":
-          description: Bad Request
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/Error"
-        "401":
-          description: Unauthorized Error
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/UnauthorizedError"
-        "403":
-          description: Forbidden Error
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/ForbiddenError"
-        "404":
-          description: Timeline not found
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/NotFoundError"
-        "409":
-          description: |
-            The tenant is already known to Pageserver in some way,
-            and hence this `/attach` call has been rejected.
-
-            Some examples of how this can happen:
-            - tenant was created on this pageserver
-            - tenant attachment was started by an earlier call to `/attach`.
-
-            Callers should poll the tenant status's `attachment_status` field,
-            like for status 202. See the longer description for `POST /attach`
-            for details.
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/ConflictError"
-        "500":
-          description: Generic operation error
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/Error"
-        "503":
-          description: Temporarily unavailable, please retry.
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/ServiceUnavailableError"
-
-
   /v1/tenant/{tenant_id}/location_config:
     parameters:
       - name: tenant_id
@@ -770,66 +662,6 @@ paths:
             application/json:
               schema:
                 $ref: "#/components/schemas/Error"
-
-  /v1/tenant/{tenant_id}/detach:
-    parameters:
-      - name: tenant_id
-        in: path
-        required: true
-        schema:
-          type: string
-      - name: detach_ignored
-        in: query
-        required: false
-        schema:
-          type: boolean
-        description: |
-          When true, allow to detach a tenant which state is ignored.
-    post:
-      description: |
-        Remove tenant data (including all corresponding timelines) from pageserver's memory and file system.
-        Files on the remote storage are not affected.
-      responses:
-        "200":
-          description: Tenant detached
-        "400":
-          description: Error when no tenant id found in path parameters
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/Error"
-        "401":
-          description: Unauthorized Error
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/UnauthorizedError"
-        "403":
-          description: Forbidden Error
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/ForbiddenError"
-        "404":
-          description: Tenant not found
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/NotFoundError"
-        "500":
-          description: Generic operation error
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/Error"
-        "503":
-          description: Temporarily unavailable, please retry.
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/ServiceUnavailableError"
-
-
   /v1/tenant/{tenant_id}/ignore:
     parameters:
       - name: tenant_id
@@ -1464,16 +1296,6 @@ components:
         generation:
           type: integer
           description: Attachment generation number.
-    TenantAttachRequest:
-      type: object
-      required:
-        - config
-      properties:
-        config:
-          $ref: '#/components/schemas/TenantConfig'
-        generation:
-          type: integer
-          description: Attachment generation number.
     TenantConfigRequest:
       allOf:
         - $ref: '#/components/schemas/TenantConfig'