If CRON=1 is in use, we shouldn't generate any output or admins may be
notified via e-mail about unnecessary warnings.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/63703

This backports all EE schema changes to CE, including EE migrations,
ensuring both use the same schema.

== Updated tests

A spec related to ghost and support bot users had to be modified to make
it pass. The spec in question assumes that the "support_bot" column
exists when defining the spec. In the single codebase setup this is not
the case, as the column is backported in a later migration. Any attempt
to use a different schema version or use of "around" blocks to
conditionally disable specs won't help, as reverting the backport
migration would also drop the "support_bot" column. Removing the
"support_bot" tests entirely appears to be the only solution.

We also need to update some foreign key tests now that we have
backported the EE columns. Fortunately, these changes are very minor.

== Backporting migrations

This commit moves EE specific migrations (except those for the Geo
tracking database) and related files to CE, and also removes any traces
of the ee/db directory.

Some migrations had to be modified or removed, as they no longer work
with the schema being backported. These migrations were all quite old,
so we opted for removing them where modifying them would take too much
time and effort.

Some old migrations were modified in EE, while also existing in CE. In
these cases we took the EE code, and in one case removed them entirely.
It's not worth spending time trying to merge these changes somehow as we
plan to remove old migrations around the release of 12.0, see
https://gitlab.com/gitlab-org/gitlab-ce/issues/59177 for more details.

Upgrade Gitaly to v1.43.0

See merge request gitlab-org/gitlab-ce!28867

It used to be the case that GitLab created symlinks for each repository
to one copy of the Git hooks, so these ran when required. This changed
to set the hooks dynamically on Gitaly when invoking Git.

The side effect is that we didn't need all these symlinks anymore, which
Gitaly doesn't create anymore either. Now that means that the tests in
GitLab-Rails should test for it either.

Related: https://gitlab.com/gitlab-org/gitaly/issues/1392#note_175619926

It takes a lot of lines to move a script

This reverts commit 744f1f2e7037f5c70c3168d9e2e89b1c327465d2, reversing
changes made to c4d930e5f54e7da07c80cc028dfc0f5c08719146.

This reverts merge request !27514

Reorganize test jobs by level

See merge request gitlab-org/gitlab-ce!27514

Files in lib will be eager loaded and hence will require haml_lint to be
loaded. Since this is only a development dependency, we can't assume
this gem will be available in production, so it should never be loaded
in production.