Rename zenith_* labels to neon_* (#3911)

## Describe your changes
Get rid of the legacy labeling. Aslo `neon_region_slug` with the same
value as `neon_region` doesn't make much sense, so just drop it. This
allows us to drop the relabeling from zenith to neon in the log
collector.

.github/helm-values/dev-eu-west-1-zeta.neon-proxy-scram.yaml

@@ -30,10 +30,9 @@ settings:
 
 # -- Additional labels for neon-proxy pods
 podLabels:
-  zenith_service: proxy-scram
-  zenith_env: dev
-  zenith_region: eu-west-1
-  zenith_region_slug: eu-west-1
+  neon_service: proxy-scram
+  neon_env: dev
+  neon_region: eu-west-1
 
 exposedService:
   annotations:

.github/helm-values/dev-us-east-2-beta.neon-proxy-link.yaml

@@ -15,10 +15,9 @@ settings:
 
 # -- Additional labels for neon-proxy-link pods
 podLabels:
-  zenith_service: proxy
-  zenith_env: dev
-  zenith_region: us-east-2
-  zenith_region_slug: us-east-2
+  neon_service: proxy
+  neon_env: dev
+  neon_region: us-east-2
 
 service:
   type: LoadBalancer

.github/helm-values/dev-us-east-2-beta.neon-proxy-scram-legacy.yaml

@@ -15,10 +15,9 @@ settings:
 
 # -- Additional labels for neon-proxy pods
 podLabels:
-  zenith_service: proxy-scram-legacy
-  zenith_env: dev
-  zenith_region: us-east-2
-  zenith_region_slug: us-east-2
+  neon_service: proxy-scram-legacy
+  neon_env: dev
+  neon_region: us-east-2
 
 exposedService:
   annotations:

.github/helm-values/dev-us-east-2-beta.neon-proxy-scram.yaml

@@ -30,10 +30,9 @@ settings:
 
 # -- Additional labels for neon-proxy pods
 podLabels:
-  zenith_service: proxy-scram
-  zenith_env: dev
-  zenith_region: us-east-2
-  zenith_region_slug: us-east-2
+  neon_service: proxy-scram
+  neon_env: dev
+  neon_region: us-east-2
 
 exposedService:
   annotations:

.github/helm-values/prod-ap-southeast-1-epsilon.neon-proxy-scram.yaml

@@ -31,10 +31,9 @@ settings:
 
 # -- Additional labels for neon-proxy pods
 podLabels:
-  zenith_service: proxy-scram
-  zenith_env: prod
-  zenith_region: ap-southeast-1
-  zenith_region_slug: ap-southeast-1
+  neon_service: proxy-scram
+  neon_env: prod
+  neon_region: ap-southeast-1
 
 exposedService:
   annotations:

.github/helm-values/prod-eu-central-1-gamma.neon-proxy-scram.yaml

@@ -31,10 +31,9 @@ settings:
 
 # -- Additional labels for neon-proxy pods
 podLabels:
-  zenith_service: proxy-scram
-  zenith_env: prod
-  zenith_region: eu-central-1
-  zenith_region_slug: eu-central-1
+  neon_service: proxy-scram
+  neon_env: prod
+  neon_region: eu-central-1
 
 exposedService:
   annotations:

.github/helm-values/prod-us-east-2-delta.neon-proxy-link.yaml

@@ -13,10 +13,9 @@ settings:
 
 # -- Additional labels for zenith-proxy pods
 podLabels:
-  zenith_service: proxy
-  zenith_env: production
-  zenith_region: us-east-2
-  zenith_region_slug: us-east-2
+  neon_service: proxy
+  neon_env: production
+  neon_region: us-east-2
 
 service:
   type: LoadBalancer

.github/helm-values/prod-us-east-2-delta.neon-proxy-scram.yaml

@@ -31,10 +31,9 @@ settings:
 
 # -- Additional labels for neon-proxy pods
 podLabels:
-  zenith_service: proxy-scram
-  zenith_env: prod
-  zenith_region: us-east-2
-  zenith_region_slug: us-east-2
+  neon_service: proxy-scram
+  neon_env: prod
+  neon_region: us-east-2
 
 exposedService:
   annotations:

.github/helm-values/prod-us-west-2-eta.neon-proxy-scram-legacy.yaml

@@ -31,10 +31,9 @@ settings:
 
 # -- Additional labels for neon-proxy pods
 podLabels:
-  zenith_service: proxy-scram
-  zenith_env: prod
-  zenith_region: us-west-2
-  zenith_region_slug: us-west-2
+  neon_service: proxy-scram
+  neon_env: prod
+  neon_region: us-west-2
 
 exposedService:
   annotations:

.github/helm-values/prod-us-west-2-eta.neon-proxy-scram.yaml

@@ -31,10 +31,9 @@ settings:
 
 # -- Additional labels for neon-proxy pods
 podLabels:
-  zenith_service: proxy-scram
-  zenith_env: prod
-  zenith_region: us-west-2
-  zenith_region_slug: us-west-2
+  neon_service: proxy-scram
+  neon_env: prod
+  neon_region: us-west-2
 
 exposedService:
   annotations: