Set kubectl.kubernetes.io/restartedAt annotation on workload redeploy

[marcelofukumoto]

Summary

Fixes #16445

Occurred changes and/or fixed issues

When redeploying a Prometheus-managed StatefulSet, only some pods were restarted.
The dashboard set only the cattle.io/timestamp annotation to trigger a rolling
update, but the Prometheus operator does not recognize this annotation and reverts
it before the rollout completes.

This PR additionally sets the standard kubectl.kubernetes.io/restartedAt annotation
on the pod template during redeploy. The Prometheus operator recognizes and preserves
this annotation, so the rolling update completes successfully for all pods.

Technical notes summary

• Added KUBECTL_RESTARTED_AT constant (kubectl.kubernetes.io/restartedAt) to
  shell/config/labels-annotations.js.
• Updated RedeployWorkloadDialog.vue to set both cattle.io/timestamp and
  kubectl.kubernetes.io/restartedAt in the pod template annotations when
  redeploying. See
  shell/dialog/RedeployWorkloadDialog.vue.
• Added unit tests covering the dual-annotation behavior, timestamp format, missing
  metadata initialization, multi-workload redeploy, and error handling.

Areas or cases that should be tested

• Redeploy a Prometheus-managed StatefulSet and verify all pods restart.
• Redeploy a standard Deployment and verify it still works as before.
• Redeploy multiple workloads at once from the list view.

Areas which could experience regressions

• Workload redeploy for any resource type (Deployment, DaemonSet, StatefulSet).
• Controllers or operators that watch pod template annotations for changes.

Screenshot/Video

Before (Ready 1/2, only one pod restarted):

After (Ready 2/2, both pods restarted successfully):

Checklist

• The PR is linked to an issue and the linked issue has a Milestone, or no issue is needed
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• The PR template has been filled out
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• The PR has automated tests or clear instructions for manual tests and the linked issue has appropriate QA labels, or tests are not needed
• The PR has reviewed with UX and tested in light and dark mode, or there are no UX changes
• The PR has been reviewed in terms of Accessibility
• The PR has considered, and if applicable tested with, the three Global Roles Admin, Standard User and User Base

[github-actions]

🔄 Auto-Retry Failed Run

The Tests workflow run 30123230857 failed and has been automatically retried.

Follow up on the retried run here if needed: https://github.com/rancher/dashboard/actions/runs/30123230857

[codyrancher]

Verified that this change adds the appropriate annotation
This applies for all resources, not just prometheus which I think it fine since it's a well known annotation. https://kubernetes.io/docs/reference/labels-annotations-taints/#kubectl-k8s-io-restart-at