Drop Publish Collection Docs workflow (ansible-collections#521)

SUMMARY
This workflow fails the CI, while at the same time I don't understand why it's even there. I think we should remove it.
ISSUE TYPE

Bugfix Pull Request

COMPONENT NAME
.github/workflows/docs-push.yml
ADDITIONAL INFORMATION
ansible-collections#518
ansible-collections#511
ansible-collections#505

Reviewed-by: mikemorency