feat(deployment)!: move nodeSelector to deployment.nodeSelector

`nodeSelector` was a top-level value although it exclusively configures the pod spec of the Gitea Deployment.
With `affinity`, `dnsConfig` and the container environment already moved into the `deployment` dict, keeping
`nodeSelector` at the root level leaves the scheduling configuration split across two places.

Moving it into the `deployment` dict continues the consolidation of Deployment-scoped values and keeps
`nodeSelector` next to the closely related `affinity` setting. The `@param` annotations are grouped with the
values they document so the generated README table stays in sync with the structure.

A deprecation check is added so that existing installations fail fast with an actionable error message. Without
it, the node selection would be dropped silently and pods could be scheduled on nodes that do not meet the
intended requirements.

BREAKING CHANGE: `nodeSelector` no longer exists. Use `deployment.nodeSelector` instead. Installations that
still set `nodeSelector` will fail unless `checkDeprecation` is set to `false`.

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

values.yaml

@@ -313,9 +313,6 @@ resources: {}
 ## @param schedulerName Use an alternate scheduler, e.g. "stork"
 schedulerName: ""
 
-## @param nodeSelector NodeSelector for the deployment
-nodeSelector: {}
-
 ## @param tolerations Tolerations for the deployment
 tolerations: []
 
@@ -325,17 +322,15 @@ topologySpreadConstraints: []
 ## @param priorityClassName priorityClassName for the deployment
 priorityClassName: ""
 
-## @param deployment.enabled Enable the deployment of Gitea.
-## @param deployment.annotations Annotations for the Gitea deployment to be created
-## @param deployment.labels Labels for the deployment
-## @param deployment.affinity Affinity for the deployment.
-## @param deployment.terminationGracePeriodSeconds How long to wait until forcefully kill the pod
-
 deployment:
+  ## @param deployment.enabled Enable the deployment of Gitea.
+  ## @param deployment.annotations Annotations for the Gitea deployment to be created
+  ## @param deployment.labels Labels for the deployment
   enabled: true
   annotations: {}
   labels: {}
 
+  ## @param deployment.affinity Affinity for the deployment.
   affinity: {}
     # nodeAffinity:
     #   requiredDuringSchedulingIgnoredDuringExecution:
@@ -372,6 +367,10 @@ deployment:
     # - name: VARIABLE
     #   value: my-value
 
+  ## @param deployment.nodeSelector NodeSelector for the deployment
+  nodeSelector: {}
+
+  ## @param deployment.terminationGracePeriodSeconds How long to wait until forcefully kill the pod
   terminationGracePeriodSeconds: 60