Remove feature gates for Repository Languages

Closes #50291

See merge request gitlab-org/gitlab-ce!21186

Resolve "Project deletion may not log audit events during group deletion"

Closes #49796

See merge request gitlab-org/gitlab-ce!21162

Fix if-check

See merge request gitlab-org/gitlab-ce!20640

Initial kaniko documentation

See merge request gitlab-org/gitlab-ce!21216

Add rake command to migrate archived traces from local storage to object storage

Closes #50232

See merge request gitlab-org/gitlab-ce!21193

Instance statistics docs

Closes #49976

See merge request gitlab-org/gitlab-ce!21099

Add ci_archive_traces_cron_worker configuration to gitlab.yml.example

See merge request gitlab-org/gitlab-ce!20583

Creates a vue component for the top bar with controllers in job log view

See merge request gitlab-org/gitlab-ce!21164

Resolve "Enable Auto DevOps instance-wide on GitLab.com"

Closes #50193

See merge request gitlab-org/gitlab-ce!21136

The repository languages feature got introduced through:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/19480. This MR
included feature flags to guard against performance regressions, which
allowed GitLab to test it on gitlab.com before the customers would be
exposed.

.com worked out fine, as shown by our internal monitoring tools, which
prompts feature gate removal.

Given the docs weren't present yet, these were added too.

Use gitlab-workhorse 6.0.0

See merge request gitlab-org/gitlab-ce!21239

Creates empty state component for job log view

See merge request gitlab-org/gitlab-ce!21195

Improved padding of top bar in IDE job trace panel

Closes #48059

See merge request gitlab-org/gitlab-ce!21222

Documentation process at GitLab

Closes #46843

See merge request gitlab-org/gitlab-ce!19902

Remove feature flag for FindAllRemoteBranches

Closes gitaly#1243

See merge request gitlab-org/gitlab-ce!21234

Fixed deleting new files creating wrong state in IDE

Closes #50255

See merge request gitlab-org/gitlab-ce!21225

Acceptance testing done through:
https://gitlab.com/gitlab-org/gitaly/issues/1312

Relatively short AT period, but given its not a hard RPC, nor anything
funky is going on, I felt that this was decent enough to remove the
feature flag.

Closes https://gitlab.com/gitlab-org/gitaly/issues/1243

Added missing html_safe on text messages.

See merge request gitlab-org/gitlab-ce!21232

Enable frozen in app/mailers/**/*.rb

See merge request gitlab-org/gitlab-ce!21147

Add Acceptance testing issue template

See merge request gitlab-org/gitlab-ce!21156

Core backports from the Premium license templates feature

See merge request gitlab-org/gitlab-ce!21212

Duplicate specs testing emoji awards on issues

Closes #45238

See merge request gitlab-org/gitlab-ce!21126

Closes #50255

Add author-link style from common.scss in EE

See merge request gitlab-org/gitlab-ce!21204

Reduce number of model instances needed in test.

Closes #49788

See merge request gitlab-org/gitlab-ce!21192

Add Czech as an available language

Closes #43227

See merge request gitlab-org/gitlab-ce!21201