feat(deployment)!: move extraVolumes and extraContainerVolumeMounts into the deployment dict

Both values are Deployment-scoped: `extraVolumes` is rendered into `spec.template.spec.volumes` and
`extraContainerVolumeMounts` only into the volumeMounts of the Gitea container. The `extra*` prefix said
nothing about that scope and left them sitting at the top level, far away from the pod- and container-scoped
settings that already live under `deployment` and `deployment.gitea`.

They therefore become `deployment.volumes` and `deployment.gitea.volumeMounts`, which makes the target
resource and container obvious from the values path alone and continues the consolidation started with
`deployment.gitea.env`, `deployment.gitea.image`, `deployment.gitea.resources` and the security contexts.

`extraInitVolumeMounts` stays where it is for now, because it targets the init containers rather than the
Gitea container. The deprecated `extraVolumeMounts` fallback is kept intact and now points at
`deployment.gitea.volumeMounts` in its documentation.

Both removed keys are covered by the deprecation check, because silently ignoring them would drop mounted
TLS certificates, custom themes or client certs and leave Gitea running with a broken or unexpected
configuration.

BREAKING CHANGE: `extraVolumes` and `extraContainerVolumeMounts` no longer exist. Use `deployment.volumes`
and `deployment.gitea.volumeMounts` instead. Installations that still set the old keys will fail to render
unless `checkDeprecation` is set to `false`.

Co-authored-by: Copilot <copilot@github.com>

values.yaml

@@ -120,6 +120,12 @@ deployment:
     #   runAsNonRoot: true
     #   runAsUser: 1000
 
+    ## @param deployment.gitea.volumeMounts Additional volume mounts.
+    volumeMounts: []
+    # - name: my-configmap-volume
+    #   mountPath: /configmap
+    #   readOnly: true
+
   ## @param deployment.nodeSelector NodeSelector for the deployment
   nodeSelector: {}
 
@@ -176,6 +182,16 @@ deployment:
   #       app.kubernetes.io/instance: gitea
 
 
+  ## @param deployment.volumes Additional volumes to mount into the pods of the Gitea deployment.
+  volumes: []
+  # - name: my-configmap-volume
+  #   config:
+  #     name: my-configmap
+  # - name: my-secret-volume
+  #   secret:
+  #     secretName: my-secret
+
+
 ## @section Gateway API
 ## See docs/gateway-api.md for full guidance.
 gatewayAPI:
@@ -594,20 +610,11 @@ postExtraInitContainers: []
 #   image: docker.io/library/busybox
 #   command: [ /bin/sh, -c, 'echo "Hello world! I am a post init container."' ]
 
-## @param extraVolumes Additional volumes to mount to the Gitea deployment
-extraVolumes: []
-# - name: postgres-ssl-vol
-#   secret:
-#     secretName: gitea-postgres-ssl
-
-## @param extraContainerVolumeMounts Mounts that are only mapped into the Gitea runtime/main container, to e.g. override custom templates.
-extraContainerVolumeMounts: []
-
 ## @param extraInitVolumeMounts Mounts that are only mapped into the init-containers. Can be used for additional preconfiguration.
 extraInitVolumeMounts: []
 
 ## @deprecated The extraVolumeMounts variable has been split two:
-## - extraContainerVolumeMounts
+## - deployment.gitea.volumeMounts
 ## - extraInitVolumeMounts
 ## As an example, can be used to mount a client cert when connecting to an external Postgres server.
 ## @param extraVolumeMounts **DEPRECATED** Additional volume mounts for init containers and the Gitea main container