What does this PR do?

Errors out and quits the manager process if credentials are not present despite being required for controllers to work

Motivation

This pattern existed for DatadogMonitor solely, but other resource controllers can benefit from it

Additional Notes

Anything else we should know when reviewing?

Minimum Agent Versions

Are there minimum versions of the Datadog Agent and/or Cluster Agent required?

• Agent: vX.Y.Z
• Cluster Agent: vX.Y.Z

Describe your test plan

• Start with usual deploy (e.g. make deploy) without creds and ensure manager process runs since no resource controllers but Agent is enabled ootb
• Enable generic resource controller and verifies it errors out and CLBOs:

  {"level":"ERROR","ts":"2025-12-09T14:56:10.809Z","logger":"setup","msg":"Unable to retrieve Datadog API credentials required by one or more enabled controllers","DatadogMonitor":false,"DatadogDashboard":false,"DatadogSLO":false,"DatadogGenericResource":true,"error":"empty API key and/or App key","stacktrace":"main.setupErrorf\n\t/workspace/cmd/main.go:509\nmain.run\n\t/workspace/cmd/main.go:265\nmain.main\n\t/workspace/cmd/main.go:204\nruntime.main\n\t/usr/local/go/src/runtime/proc.go:285"}

  ╰─❯ k get pod
  NAME                                        READY   STATUS             RESTARTS      AGE
  datadog-operator-manager-67b79b87df-4t6zc   0/1     CrashLoopBackOff   2 (20s ago)   44s

• Add api key and app key foo and verifies it recovers/is able to run without the error

Checklist

• PR has at least one valid label: bug, enhancement, refactoring, documentation, tooling, and/or dependencies
• PR has a milestone or the qa/skip-qa label