Remove finalizer based deletion ordering functionality

[turkenh]

What problem are you facing?

Provider Kubernetes introduced a finalizer based deletion ordering solution before Crossplane introduces Usages. The functionality works fine most of the time, however, may cause ending up with stuck resources with finalizers not removed especially under heavy conditions where multiple Objects deleted in parallel or provider gets restarted (just theory, haven't dug deeper).

We should deprecate this stop-gap solution in favor of Crossplane Usages to avoid the maintenance burden and confusion with multiple solutions to the same problem.

How could Crossplane help solve your problem?

Deprecate & remove finalizer based deletion ordering functionality. //cc @morningspace

[rperez95]

Hi @turkenh,

I understand the reasoning behind deprecating the finalizer-based deletion ordering functionality, but we're concerned about how it might affect certain use cases.

For instance, we rely on this feature to prevent deletion of pre-created k8s secrets used by some of our compositions. As far as we know, the use of Usages is restricted to Crossplane resources, which does not include k8s secrets.

We use Usages to deletion ordering, but we also use the finalizer-based functionality to ensure that k8s secrets are not deleted before the managed resources deployed by our compositions are fully deleted.

Could you clarify whether an alternative mechanism would be introduced to handle such scenarios, or provide guidance on how to address this gap if the finalizer-based approach is removed?