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