This adds Ruby 2.6 support.

Docs: Merge EE doc/​customization to CE

See merge request gitlab-org/gitlab-ce!27604

Resolve "Sort by due date and popularity in both directions"

Closes #50926

See merge request gitlab-org/gitlab-ce!25502

Resolve "Include time window parameters in the URL query string"

Closes #59365

See merge request gitlab-org/gitlab-ce!27230

Cache current working directory to speed up Rubocop

Closes #61383

See merge request gitlab-org/gitlab-ce!28066

CE Backport of tracking uninstall button click

See merge request gitlab-org/gitlab-ce!28012

Add @katrinleinweber as German proofreader

See merge request gitlab-org/gitlab-ce!24331

Update Releases permissions docs

See merge request gitlab-org/gitlab-ce!27935

Guest users now can read releases, except for items related to source
code.

Releated:
  https://gitlab.com/gitlab-org/gitlab-ce/issues/56838
  https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/27247

Set timezone as GMT in Jest config file

Closes #59952

See merge request gitlab-org/gitlab-ce!27738

Allow guests users to access project releases

Closes #56838

See merge request gitlab-org/gitlab-ce!27247

This is step one of resolving
https://gitlab.com/gitlab-org/gitlab-ce/issues/56838.

Here is what changed:
- Revert the security fix from bdee9e84.
- Do not leak repository information (tag name, commit) to guests in API
responses.
- Do not include links to source code in API responses for users that do
not have download_code access.
- Show Releases in sidebar for guests.
- Do not display links to source code under Assets for users that do not
have download_code access.

GET ':id/releases/:tag_name' still do not allow guests to access
releases. This is to prevent guessing tag existence.

Docs: Update docs related to CI variables

See merge request gitlab-org/gitlab-ce!27786

Add `Variable Types` section to explain supported variable types and
update example and related screenshots.

Include all queries in the performance bar summary

Closes #61372

See merge request gitlab-org/gitlab-ce!28063

Internationalisation of reports directory

See merge request gitlab-org/gitlab-ce!27742

This is one of many MRs opened in order to improve the overall
internationalisation of the GitLab codebase.

i18n documentation
https://docs.gitlab.com/ee/development/i18n/externalization.html

This saves thousands of getcwd() system calls and improves the
performance of running Rubocop, which is also used by HAML linting.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/61383

Rails 5.1's `exec_no_cache` doesn't call `async_exec` any more, but
`exec_params`: https://github.com/rails/rails/pull/33188

This means that the DB summary in the performance bar was wrong. The
individual query details were still correct (we subscribe to
ActiveRecord events for those).

We can remove this once the upstream PR to peek-pg is in a release and
we update to use that release.

Pass excluded paths to SAST and DS

See merge request gitlab-org/gitlab-ce!28018

Propagate DS_EXCLUDED_PATHS to dependency_scanning job,
and SAST_EXCLUDED_PATHS and SAST_BANDIT_EXCLUDED_PATHS to sast job.
This makes possible to excluded certains paths from SAST reports
and Dependency Scanning reports, respectively.

Impove the performance of expanding full diff

Closes #58597

See merge request gitlab-org/gitlab-ce!27413

Sort feature set table by stage

See merge request gitlab-org/gitlab-ce!27940

Resolve "Consider setting RSpec `full_backtrace` only in CI"

Closes #61365

See merge request gitlab-org/gitlab-ce!28051

Internationalisation of javascript/s* directories

See merge request gitlab-org/gitlab-ce!27745

This is one of many MRs opened in order to improve the overall
internationalisation of the GitLab codebase.

i18n documentation
https://docs.gitlab.com/ee/development/i18n/externalization.html

Merge branch '9971-move-ee-differences-for-app-assets-javascripts-notes-components-note_form-vue-ce' into 'master'

EE Backport to CE of EE!11151

See merge request gitlab-org/gitlab-ce!27824

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/58597

Switch to sassc-rails for faster stylesheet compilation

Closes #18432

See merge request gitlab-org/gitlab-ce!26224

[docs] Clarify gitlab.rb settings for modifying pipeline schedule worker

See merge request gitlab-org/gitlab-ce!27725

Whitelist query limits for internal API

Closes gitlab-ee#11450

See merge request gitlab-org/gitlab-ce!28037

When creating a merge request for push options, there may be over 100
queries that are run to create a merge request. Even after we reduce the
number of queries by disabling the Sidekiq jobs, it appears we still
hover near this limit.

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/11450