* master: (140 commits)
  Add Gitter room link to I want to contribute since you always have questions
  Use workhorse 3.4.0
  chore: remove symbolic link
  Add memoization for properties
  Resolve "Allow QA tests to run with `CHROME_HEADLESS=false`"
  Resolve "Add graph value to hover"
  Fix slash commands dropdown description
  disables the shortcut to the issue boards when issues are disabled
  Fix static analysys
  Disable STI of ActiveRecord. Refactoring specs.
  Fix StaticSnalysys
  Fix change log
  Add changelog
  Revert bulk_insert and bring back AR insert(one by one)
  Add a new test for emptified params
  Use batch update for Service deactivation
  Fix query to look for proper unmanaged kubernetes service
  Fix static anylysy
  Use bulk_insert instead of AR create
  Opitmize migration process by using both unmanaged_kubernetes_service and kubernetes_service_without_template
  ...

Use gitlab-workhorse 3.4.0

Closes gitaly#886

See merge request gitlab-org/gitlab-ce!16285

Add Gitter room link to I want to contribute since you always have questions

See merge request gitlab-org/gitlab-ce!16173

Resolve "Fix wrong output protocol pattern when adding custom domain to Pages"

Closes #28260

See merge request gitlab-org/gitlab-ce!16279

Update rack-cors from 0.4.0 to 1.0.2

Closes #41199

See merge request gitlab-org/gitlab-ce!16183

Fix typo in writing_documentation.md

See merge request gitlab-org/gitlab-ce!16276

Merge branch '40418-migrate-existing-data-from-kubernetesservice-to-clusters-platforms-kubernetes' into 'master'

Migrate existing data from KubernetesService to Clusters::Platforms::Kubernetes

Closes #40418

See merge request gitlab-org/gitlab-ce!15589

Upgrade scss-lint to 0.56.0

Closes #41754

See merge request gitlab-org/gitlab-ce!16278

Run background migrations with a minimum interval

Closes #41624

See merge request gitlab-org/gitlab-ce!16230

Resolve "Allow QA tests to run with `CHROME_HEADLESS=false`"

Closes gitlab-qa#149

See merge request gitlab-org/gitlab-ce!16248

Resolve "No Rendering of emoji's in Group-Overview after update"

Closes #40549

See merge request gitlab-org/gitlab-ce!16098

Remove the Commit#tree method

See merge request gitlab-org/gitlab-ce!16236

Remove unused push_code_to_protected_branches

Closes #38056

See merge request gitlab-org/gitlab-ce!16253

Incorporate RemoteService.FetchInternalRemote Gitaly RPC

Closes gitaly#857

See merge request gitlab-org/gitlab-ce!16140

Move invites spinach test to Rspec

See merge request gitlab-org/gitlab-ce!16126

Move explore groups spinach test to RSpec

See merge request gitlab-org/gitlab-ce!16129

Resolve "Add graph value to hover"

Closes #38030

See merge request gitlab-org/gitlab-ce!16261

Fix slash commands dropdown description

See merge request gitlab-org/gitlab-ce!16125

disables the shortcut to the issue boards when issues are disabled

Closes #41244

See merge request gitlab-org/gitlab-ce!16020

Protected branch is now created for default branch on import

Closes #3968

See merge request gitlab-org/gitlab-ce!16198

Opitmize migration process by using both unmanaged_kubernetes_service and kubernetes_service_without_template