CE Upstream - Wednesday

Closes gitlab-ce#29414

See merge request !1537

Merge branch '1811-very-poor-performance-creating-merge-request-regression-in-9-0-often-hits-60-seconds-timeout-on-small-requests' into 'master'

Resolve "Very poor performance creating merge request, regression in 9.0 - often hits 60 seconds timeout on small requests"

Closes #1811

See merge request !1522

Also disabled assets warming for Capybara/RSpec and remove a check to
skip assets warming when ./tmp/cache/assets/test exists because assets
are now served by webpack-dev-server.
Signed-off-by: Rémy Coutable <remy@rymai.me>

Use `:empty_project` in worker, view, task, serializer, policy, migration, and mailer specs

See merge request !1524

CE -> EE port: cleanup application settings spec ee

See merge request !1498

Update database source documentation for 9.6 compatibility

Closes #1746

See merge request !1543

bumps gitlab shell version

See merge request !10329

Test docs internal links check

See merge request !9509

A new MR won't have an author necessarily, so use the current user in
that case.

Instead of performing `git log` for each file that's changed, do it for
all files at once. This stops git having to load large packfiles once
for each file in an MR.

This is always a suggestion, so the change in behaviour should be
fine. Increase the number of commits counted by squaring it, to allow
for the fewer calls to `git log`.

This is analogous to `git log -- foo bar baz`, but not the same as
`Gitlab::Git::Repository#log(path: 'foo bar baz')`, which would run `git
log -- 'foo bar baz'`.

adds timeout option to push mirrors

Closes #1907

See merge request !1439

CE -> EE port: System notes meta data

See merge request !1526

Add metadata for system notes

See merge request !9964

Ensure empty string & non-numeric values also result in an error.

The ApplicationSetting#restricted_visibility_levels= now takes care of
converting string formatted levels to integers.

EE already includes specs for the ApplicationSettingsController, so
ensure future changes will be easier to merge to EE.

Prevent private group disclosure via parent_id

See merge request !2077

Use full path for moving directories when changing namespace path

See merge request !2078

Reset container width when switching to pipelines MR tab

Closes #29539

See merge request !10169

Port of '23674-simplify-milestone-summary' to EE

See merge request !1511

Resolve "Simplify milestone summary"

Closes #23674

See merge request !10096

Add shortcuts and counters to MRs and issues in navbar

Closes #29866

See merge request !10314

[ci skip]

Remove jQuery from IPython notebook viewer

See merge request !10315

Fix admin projects page in admin area

See merge request !10277

Fix custom protected branch pattern jumping scroll position to top -- EE merge edition

Closes gitlab-ce#30149

See merge request !1523