🐛 all: only set finalizers if deletionTimestamp is not set

[sbueringer]

Signed-off-by: Stefan Büringer buringerst@vmware.com

What this PR does / why we need it:
As reported in #8946 Cluster API today tries to add a finalizer even if objects already has a deletionTimestamp set.

This results in the following error message from the APIserver:

"Reconciler error" err="Cluster.cluster.x-k8s.io "sgcluster" is invalid: metadata.finalizers: Forbidden: no new finalizers can be added if the object is being deleted, found new finalizers []string{"cluster.cluster.x-k8s.io"}"

This case especially occurs if a finalizer of another controller is removed after our finalizer.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Related to #8946

[sbueringer]

/test pull-cluster-api-e2e-full-main

[sbueringer]

cc @enxebre given somewhat related discussion last week around Machine finalizer

[enxebre]

Make sense to me. Alternatively we could move up reconcile deletion logic to run before Add finalizer logic

[sbueringer]

Make sense to me. Alternatively we could move up reconcile deletion logic to run before Add finalizer logic

I think moving the finalizer down or the reconcileDelete up is in most cases the same change :)

[killianmuldoon]

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 68d5b76224ea18a74178743f2525b1b02dec0dfa

[enxebre]

/lgtm
Deferring to @fabriziopandini final tag to ack his concerns are adressed

[fabriziopandini]

/lgtm
/approve

[k8s-ci-robot]

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[killianmuldoon]

/area api