This is an ID-less table with just three columns: an association to the merge
request diff the commit belongs to, the relative order of the commit within the
merge request diff, and the commit SHA itself.

Previously we stored much more information about the commits, so that we could
display them even when they were deleted from the repo. Since 8.0, we ensure
that those commits are kept around for as long as the target repo itself is, so
we don't need to duplicate that data in the database.

This reverts merge request !12127

This cop has been renamed to ActiveRecordSerialize to match the way
"ActiveRecord" is usually written.

This is allowed for existing instances so we don't end up 76 offenses
right away, but for new code one should _only_ use this if they _have_
to remove non database data. Even then it's usually better to do this in
a service class as this gives you more control over how to remove the
data (e.g. in bulk).

This removes the need for relying on Rails' "dependent" option for data
removal, which is _incredibly_ slow (even when using :delete_all) when
deleting large amounts of data. This also ensures data consistency is
enforced on DB level and not on application level (something Rails is
really bad at).

This commit also includes various migrations to add foreign keys to
tables that eventually point to "projects" to ensure no rows get
orphaned upon removing a project.

https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/2112

- Don't use `request.env['omniauth.params']` if it isn't present.

- Remove the `saml` section from the `gitlab.yml` test section. Some tests
  depend on this section not being initially present, so it can be overridden
  in the test. This MR doesn't add any tests for SAML, so we didn't really need
  this in the first place anyway.

- Clean up the test -> omniauth section of `gitlab.yml`

- Disable an ESLint check rather than work around it (by
  converting `OAuthRememberMe` from a regular class to a
  static class.

- Scope `$` calls inside `OAuthRememberMe`

- Change double quotes to single quotes.
- Why is `OmniAuth.config.full_host` being reassigned in the integration test?
- Use `map` over `map!` to avoid `dup` in the `gitlab:info` rake task
- Other minor changes

- There was previously a test for `saml` login in `login_spec`, but this didn't
  seem to be passing. A lot of things didn't seem right here, and I suspect that
  this test hasn't been running. I'll investigate this further.

- It took almost a whole working day to figure out this line:

    OmniAuth.config.full_host = ->(request) { request['REQUEST_URI'].sub(request['REQUEST_PATH'], '') }

  As always, it's obvious in retrospect, but it took some digging to figure out
  tests were failing and returning 404s during the callback phase.

- Test all OAuth providers - github, twitter, bitbucket, gitlab, google, and facebook

- Pass a `remember_me` query parameter along with the initial OAuth request, and
  pick this parameter up during the omniauth callback from
  request.env['omniauth.params']`.

- For 2FA-based login, copy the `remember_me` param from `omniauth.params` to
  `params`, which the 2FA process will pick up.

- For non-2FA-based login, simply call the `remember_me` devise method to set
  the session cookie.

This reverts merge request !11963

Closes #34711

Closes #34670

Support noticed that a number of exceptions, such as
"Encoding::CompatibilityError (incompatible character encodings: UTF-8 and
ASCII-8BIT)", failed to report to Sentry. The `rescue_from` in the
ApplicationController prevented these exceptions from being recorded.
This change ensures that these exceptions are properly captured.

This reverts merge request !12557