Handle `milestones: nil` in `Release::CreateService#execute`

See merge request gitlab-org/gitlab!47229

This commit updates `Releases::CreateService` to handle cases where
`#execute` is passed a Hash with `milestones: nil`. In this case, the
service should behave as if `milestones: []` was passed.

Adding note on migrations to Gitlab Docs

See merge request gitlab-org/gitlab!47703

Move user ee spec to correct directory

See merge request gitlab-org/gitlab!47558

Boards - Move issue using VueX action

See merge request gitlab-org/gitlab!47866

Remove DOMContentLoaded Eventlisteners

See merge request gitlab-org/gitlab!47775

Fixed UI issues in merge conflict app

See merge request gitlab-org/gitlab!47916

On-demand loading of select2 CSS

See merge request gitlab-org/gitlab!44319

Fix for loading select2 on demand

Fix of general select2 setup + linting fixes

Typo in exclude for stylelint
Added lazy CSS Loading for all Select2 instances

Fixed Spec around Select 2 + no-nesting  rules

Add option to remove legacy Tiller server

See merge request gitlab-org/gitlab!47457

Since GitLab 13.2, a local Tiller has been used for Helm 2 clusters,
and as of GitLab 13.6, Helm 3 is used by default. This re-adds the
Helm application row when the Helm record is present, to give existing
users an easy option to remove the unused Tiller server from their
cluster.

Detail path issues between windows and linux

See merge request gitlab-org/gitlab!43020

Windows runners have a non-usable path syntax on a Linux server

Edit CI schedules doc according to Vale suggestions

See merge request gitlab-org/gitlab!47811

Edit CI Variables doc according to Vale

See merge request gitlab-org/gitlab!46957

Render markdown snippets on Geo secondary sites

See merge request gitlab-org/gitlab!46812

Utilize `ProjectSetting#has_vulnerabilities` attribute to get projects

See merge request gitlab-org/gitlab!47259

Fix kwargs deprecation warnings for jwt_token helper

See merge request gitlab-org/gitlab!47791

Update quarantine tag

See merge request gitlab-org/gitlab!47986

Update Gitaly docs to mention TLS client certificate support

See merge request gitlab-org/gitlab!47954

Move quality_test_cases factory to EE folder

See merge request gitlab-org/gitlab!47829

Enable FF ci_bridge_dependency_variables by default

See merge request gitlab-org/gitlab!47905

Revert " Add custom scanner filter to security dashboard"

See merge request gitlab-org/gitlab!47994

Fix kwargs deprecation warnings in snowplow tracking specs

See merge request gitlab-org/gitlab!47913

Add caching for ES migration_has_finished?

See merge request gitlab-org/gitlab!47896

Review feedback

Migrate environment dropdown

See merge request gitlab-org/gitlab!46193

Revert "Merge branch 'mo-add-codequality-feature-flag' into 'master'"

See merge request gitlab-org/gitlab!47990

This reverts merge request !46540

Remove unnecessary `rules` references from base secure jobs

See merge request gitlab-org/gitlab!47691

This reverts merge request !47938

The original issue hasn't recurred, but the new one has.

Render scan information only when it is provided in Vulnerability

See merge request gitlab-org/gitlab!47958

Adds warnings to API response for linting

See merge request gitlab-org/gitlab!47037

Docs: CI Get Started redo

See merge request gitlab-org/gitlab!47715