feat(servicecredentialbinding): make circuit breaker resumable

[Kukkerem]

Closes: #337

Problem

When a ServiceCredentialBinding reaches its create-attempt limit, it stops retrying for good. The only way to recover is to delete and recreate the resource. The limit is also hard-coded to 5.

Fix

• When the limit is reached, the provider sets the annotation servicecredentialbinding.cloudfoundry.crossplane.io/max-retry-exceeded to the time it tripped, removes the create-attempts counter, and emits a CreateAttemptsExhausted Warning event.
• While the annotation is present, reconciliation is paused and the provider makes no Cloud Foundry calls. Ready=False explains how to resume.
• Removing the annotation resumes reconciliation straight away, with the full attempt budget.
• Deleting the resource still works while it is paused: the finalizer is cleared and retired keys are cleaned up. Key rotation is skipped while the resource is being deleted.
• New flag --scb-max-create-attempts (env SCB_MAX_CREATE_ATTEMPTS), default 5. A value below 1 stops the provider at startup.
• Docs: new "Create failure protection" section in docs/end-user-guides/deploy-workload-provider-cf.mdx.

Testing

• Unit tests cover tripping at the limit, pausing, resuming, deleting while paused, and a custom limit.
• make reviewable passes (generate, lint, unit tests).
• Manual:
  • Trip the breaker with a binding that fails. The annotation, the Warning event and the Ready=False message appear.
  • While paused, the provider makes no further Cloud Foundry calls.
  • Removing the annotation reconciles straight away and the binding gets created.
  • Deleting a paused binding completes.
  • Setting --scb-max-create-attempts changes the limit.