Backport finalizer fixes to release-v1.39

[caseydavenport]

Backports several finalizer-related fixes that address flaky test failures and uninstall stability issues:

• Delay finalizer removal until all pods are deleted #4179 — Delay finalizer removal until all pods are deleted, fixing lingering pod issues during uninstall
• Add a requeue when waiting for finalizer cleanup #4209 — Add requeue when waiting for finalizer cleanup, so controllers don't stall waiting on pod deletion they're not watching
• Fix finalizer race between whisker and goldmane controllers #4492 — Switch finalizer patching to MergeFromWithOptimisticLock to fix a race between whisker and goldmane controllers where concurrent patches silently clobbered each other