[DPE-5932] Remove cert-available check for CA rotation

[phvalguima]

This PR removes one of the filters that was causing a race condition at CA rotation + large deployments. It fixes the CA rotation for large deployments in our CI.

Closes #500

[reneradoi]

Hey Pedro, I think this change makes sense. We had a couple of changes on the whole process in the last weeks, therefore the condition if not self.ca_rotation_complete_in_cluster() in _on_certificate_available is now probably obsolete. The original need for it was to make sure nothing gets updated during the rollout of the new CA: no certs, no secrets, no ca-bundle.

Your assumption of a race condition seems plausible, at least the integration tests look good after the change. Important tough: Make sure the condition if not self.ca_rotation_complete_in_cluster() stays in store_new_tls_resources(), otherwise the certs might get updated during the rollout of the new CA.

[reneradoi]

Hey @phvalguima the unit tests look fine now. The only thing that needs to be adjusted is the comments in line 1581 and 1690 of test_opensearch_tls.py saying In case any stage of a CA cert rotation is being processed, further 'certificate-available' events are deferred.

Other than that, the change can be merged from my point of view.