test: don't delete namespaces in unit tests

[mandre]

Namespace deletion is asynchronous — a deleted namespace enters a Terminating state before being fully removed. If the next test's GenerateName produces a suffix that collides with a still-Terminating namespace, the API server returns a hard error rather than retrying with a new name.

Since all unit tests run against an envtest API server that is torn down in AfterSuite, explicit namespace deletion is unnecessary. Remove the DeferCleanup blocks that delete namespaces to eliminate the flake.

Closes #850

[dlaw4608]

Nice one LGTM, noticed the same namespace deletion is included in the upload_image.py file

openstack-resource-controller/internal/controllers/image/upload_test.go

Lines 200 to 204 in ef6119d

	Expect(k8sClient.Create(ctx, orcImage)).To(Succeed(), "create ORC Image")
	DeferCleanup(func() {
	Expect(k8sClient.Delete(ctx, namespace)).To(Succeed(), "delete ORC Image")
	})

would it be worth it to carry the same rationale as above and let the envtest tear down handle deletion in AfterSuite in this case too, WDYT?

[winiciusallan]

I think this partially solves the problem. When one test produces a suffix that clashes with an existing namespace, regardless it's being deleted or not, don't the apiserver return an error about trying to create an existing namespace?