9) Using an opt-out namespaceSelector to exclude namespaces (as in operator: DoesNotExist)
10) Using an opt-in namespaceSelector to run in included-only mode (as in operator: Exist).

These cases are about testing the correct creating of the MutatingWebhookConfiguration.
Therefore they should go into the operator's suite.

We can test the two behaviors by:
1. creating the PodPlacementConfig with either the opt-in (e.g. using the In operator for the namespace selector), or opt-out namespaceSelector (e.g., using the DoesNotExist operator for the namespace selector)
2. Create more ephemeral namespaces according to the need of the case (opt-in/opt-out)
3. Verify a deployment gets the proper affinity