fix(controller): DescribeVersion on NotRegistered Versions to prevent pre-mature scaledown of said versions

[Shivs11]

Summary

• describe Kubernetes-backed Worker Deployment Versions that are absent from deployment summaries before treating them as NotRegistered
• add an integration regression test using a real pinned workflow while filtering the version from deployment summaries

Behavioral impact

• Versions present in VersionSummaries retain their existing status precedence and rollout behavior.
• A Kubernetes build ID missing from VersionSummaries now triggers one DescribeVersion call:
  • success restores the version to controller state and prevents unsafe deletion
  • NotFound preserves the existing NotRegistered cleanup path
  • any other error stops reconciliation instead of continuing with incomplete state and potentially deleting the deployment
• A successfully described inactive target version can use the existing progressive-rollout unversioned-poller check.
• No planner, CRD, or public API behavior changes.

Testing

• go test ./internal/temporal ./internal/controller ./internal/planner -count=1
• go test -v -tags test_dep ./internal -run 'TestIntegration/missing-summary-version-is-described-before-deletion' -count=1
• go vet ./internal/temporal ./internal/controller ./internal/planner
• git diff --check

Closes #550

[CLAassistant]

All committers have signed the CLA.

[Shivs11]

going to hold off on this one for now, and wait for @carlydf's PR to go through!

[jaypipes]

would be great to put a log line in here:

l.Info(
    "warning: Kubernetes Deployment not found in WorkerDeployment VersionSummaries. "+
        "Possible inconsistent Temporal server state.",
    "buildID", buildID,
)

[jaypipes]

Suggested change

	return nil, fmt.Errorf("describe worker deployment version for buildID %q returned no registered status", buildID)
	return nil, fmt.Errorf("describe worker deployment version for buildID %q returned NotRegistered status", buildID)

[jaypipes]

Technically, this should check whether err was NotFound...