Pick revert of `require-all-templates-to-include-default-stages'
What does this MR do?
This picks the https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/26954 reverted as part of https://gitlab.com/gitlab-org/gitlab-ce/issues/60106
Resolves https://gitlab.com/gitlab-org/gitlab-ce/issues/60106
Does this MR meet the acceptance criteria?
Conformity
Edited by Kamil Trzciński