test: wait for storage controller readiness (#6930)

## Problem
Starting up the pageserver before the storage controller is ready can
lead
to a round of reconciliation, which leads to the previous tenant being
shut down.
This disturbs some tests. 

## Summary of changes
Wait for the storage controller to become ready on neon env start-up.

Closes https://github.com/neondatabase/neon/issues/6724

control_plane/src/attachment_service.rs

@@ -308,7 +308,7 @@ impl AttachmentService {
             )],
             background_process::InitialPidFile::Create(self.pid_file()),
             || async {
-                match self.status().await {
+                match self.ready().await {
                     Ok(_) => Ok(true),
                     Err(_) => Ok(false),
                 }
@@ -522,8 +522,8 @@ impl AttachmentService {
     }
 
     #[instrument(skip(self))]
-    pub async fn status(&self) -> anyhow::Result<()> {
-        self.dispatch::<(), ()>(Method::GET, "status".to_string(), None)
+    pub async fn ready(&self) -> anyhow::Result<()> {
+        self.dispatch::<(), ()>(Method::GET, "ready".to_string(), None)
             .await
     }
 

test_runner/regress/test_sharding_service.py

@@ -179,9 +179,6 @@ def test_node_status_after_restart(
     env.attachment_service.stop()
     env.attachment_service.start()
 
-    # Initially readiness check should fail because we're trying to connect to the offline node
-    assert env.attachment_service.ready() is False
-
     def is_ready():
         assert env.attachment_service.ready() is True