Migrate GitHub workflows to prow jobs

[ivanvc]

This was discussed during the community meeting and in #17 (comment).

Move the workflows to the prow infrastructure, and then delete the workflows from the repository.

Completion tracking:

• unit tests - etcd: import operator test presubmit job kubernetes/test-infra#34090
• e2e tests - etcd: add pull-etcd-operator-test-e2e job kubernetes/test-infra#34107
• linter - etcd operator: add lint pre and postsubmit jobs kubernetes/test-infra#34162

[ivanvc]

/assign

[ivanvc]

@jmhbnz, do we want to enable /ok-to-test, here, too? It would be a good idea (and a good first issue).

[jmhbnz]

@jmhbnz, do we want to enable /ok-to-test, here, too? It would be a good idea (and a good first issue).

Yes I think we should enable same suite of plugins we use on other etcd repositories, we can do it as a separate good first issue certainly 🙏🏻

[ivanvc]

I'll close this issue as the jobs are now running in the Prow infra. Thanks, @soma00333, for your help with the missing postsubmits 🎉 :)

[soma00333]

Hi @ivanvc
Good day
I appreciate your quick review and hard work on this😊