Further remove code branches by database type (EE)
What does this MR do?
Another pass on EE similar to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/31102
This change removes code where we branch out by type of database. In https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/29608, we already removed the if mysql?; ... else ... end
parts. Here we take the other perspective and remove if postgresql?; ... else ... end
branches.
Relates to https://gitlab.com/gitlab-org/gitlab-ce/issues/52442 but there's no other issue for it.
Does this MR meet the acceptance criteria?
Conformity
Edited by Andreas Brandl