Feature spec for merge train

Closes #12081

See merge request gitlab-org/gitlab-ee!14090

Unquarantine the branches E2E test

Closes gitlab-org/quality/nightly#62

See merge request gitlab-org/gitlab-ce!29828

Docs: Added source upgrade guides for 12.0.0

See merge request gitlab-org/gitlab-ce!29795

Document Usage Quotas group settings page

Closes #63022

See merge request gitlab-org/gitlab-ce!29599

Review Toolbar: Add closing tag

See merge request gitlab-org/gitlab-ee!14264

Add zoom call section in issue data page

See merge request gitlab-org/gitlab-ce!29815

Add changelog entry for the new operations_feature_flags_clients.token_encrypted column

See merge request gitlab-org/gitlab-ce!29820

We missed to add this in
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/29320.

Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/57918

Unquarantine merge tests

Closes gitlab-org/quality/nightly#93 and gitlab-org/quality/nightly#94

See merge request gitlab-org/gitlab-ce!29833

Crosslink Mattermost integrations, simplify components list

See merge request gitlab-org/gitlab-ce!29317

Allow developers to delete tags

Closes #52954

See merge request gitlab-org/gitlab-ce!29668

This commit adds
 - feature specs
  - to test the ability of a user with "developer" permission
    to delete tags in repositories.
 - documentation

Adding feature spec

Fix Container Scanning job with K8S runners

Closes gitlab-ee#11448

See merge request gitlab-org/gitlab-ce!29706

Add note about not translating API messages.

See merge request gitlab-org/gitlab-ce!29748

Add identity information to external authorization requests

See merge request gitlab-org/gitlab-ce!29461

Issue: https://gitlab.com/gitlab-org/gitlab-ce/issues/61201#

Fix missing API notification flags for Microsoft Teams

See merge request gitlab-org/gitlab-ce!29824

Demote new section

See merge request gitlab-org/gitlab-ce!29829

Un-quarantine OAuth spec

Closes gitlab-org/quality/nightly#100

See merge request gitlab-org/gitlab-ce!29764

Fix GeoNodeStatus#update_cache! spec

Closes #12263

See merge request gitlab-org/gitlab-ee!14267

Un-quarantine instance level project template spec

Closes gitlab-org/quality/staging#51

See merge request gitlab-org/gitlab-ee!14245