Create idea of read-only database

Closes #2855, #3398, #3399, and #3505

See merge request gitlab-org/gitlab-ee!2954

Merge branch '38771-skip-fork-mirror-and-import-start-if-the-worker-was-reset-without-cleanup' into 'master'

Import/Fork/Mirror jobs now skip starting transition if the worker was killed…

See merge request gitlab-org/gitlab-ee!3071

Ensure we set SUITE_FLAKY_RSPEC_REPORT_PATH to nil in RspecFlaky::Listener spec

Closes #38872

See merge request gitlab-org/gitlab-ce!14736

Geo: Add documentation to restart after moving the files out

See merge request gitlab-org/gitlab-ee!3088

[ci skip]

Resolve "Improve visibility of deploy boards"

Closes #3328

See merge request gitlab-org/gitlab-ee!2984

Upgrade doorkeeper-openid_connect

See merge request gitlab-org/gitlab-ce!14372

Use API v4 during Geo OAuth authentication

Closes #3624

See merge request gitlab-org/gitlab-ee!3082

Import/Fork/Mirror jobs now skip starting transition if the worker was killed and reset without proper cleanup.

Limit the huge cross-database pluck for LFS objects and attachments

Closes #3645

See merge request gitlab-org/gitlab-ee!3075

[EE] Fix flaky examples tracking

See merge request gitlab-org/gitlab-ee!3065

Replace the 'project/merge_requests.feature' spinach test with an rspec analog

See merge request gitlab-org/gitlab-ee!3079

Geo - Selective replication allows admins to select any groups

Closes #3258

See merge request gitlab-org/gitlab-ee!2779

Rebase using git worktree

Closes #1604

See merge request gitlab-org/gitlab-ee!2962

`/api/v3/user` and `/api/v4/user` behave exactly the same, so prepare
for removal of API v3, and use v4 instead.

Closes gitlab-org/gitlab-ee#3624.

pgloader docs

Closes #2799

See merge request gitlab-org/gitlab-ee!3077

EE Port of "Lock discussion for issues and merge requests"

See merge request gitlab-org/gitlab-ee!3061

This repeats the approach used in #3629 to limit the huge `NOT IN`
fragment.

Closes #3645

Instead of checking it in the User model, move it as deep as possible
to avoid future mistakes.

`CacheMarkdownField#refresh_markdown_cache!` is splitted out in:
- `CacheMarkdownField#refresh_markdown_cache`: This does the same as
  before, but does never write to database.
- `CacheMarkdownField#refresh_markdown_cache!`: This calls the
  previous method, and tries to write to database, if possible.

Don't create todos for old issue assignees

Closes #3642

See merge request gitlab-org/gitlab-ee!3064

Signed-off-by: Rémy Coutable <remy@rymai.me>

Document how to use pgloader

Closes gitlab-ee#2799

See merge request gitlab-org/gitlab-ce!13109

# Conflicts:
#	doc/user/permissions.md

[ci skip]

Save Geo files to a temporary file and rename after success

Closes #3618 and #3242

See merge request gitlab-org/gitlab-ee!3058

Geo: Fix attachments/avatars saving to the wrong directory

Closes #3634

See merge request gitlab-org/gitlab-ee!3068