Make pipeline failure Slack notifications prettier and more informative

Closes #32495

See merge request gitlab-org/gitlab-ce!27683

Extract resource_label_events API shared examples

See merge request gitlab-org/gitlab-ce!31156

Refactor elements used by ci_variable and ::CICD

See merge request gitlab-org/gitlab-ce!30922

Many elements defined in the QA framework in ci_variable.rb
call elements and methods that are not framework specific.

Fix these issues, as well as use data-qa-selector s

Add frozen_string_literal to spec/factories

See merge request gitlab-org/gitlab-ce!31129

fix: updates labels to include units in metrics

Closes #59325

See merge request gitlab-org/gitlab-ce!30330

This MR updates the y_label values and the label
values in common_metrics and cluster_metrics to
append the units of measurement to the labels.

Fix pid discovery for Unicorn in PidProvider

See merge request gitlab-org/gitlab-ce!31056

Remove code related to object hierarchy and MySQL

Closes #65056 and #65055

See merge request gitlab-org/gitlab-ce!31095

Find build by sha from ref

Closes #64534 and #45697

See merge request gitlab-org/gitlab-ce!30843

Remove fallback to deployment_platform_cluster in `DeploymentMetrics`

See merge request gitlab-org/gitlab-ce!31126

Add severity for vulnerabilities

See merge request gitlab-org/gitlab-ce!31146

(CE Port) Add MR table component for Productivity Analytics

See merge request gitlab-org/gitlab-ce!30975

Fix error rendering submodules in MR diffs when there is no .gitmodules

See merge request gitlab-org/gitlab-ce!31162

Prefer `flat_map` over `map` + `flatten`

See merge request gitlab-org/gitlab-ce!31144

Convert several occurrences of `map` + `flatten` to
`flat_map` where applicable.

Without this change, we get a NoMethodError on nil

Add development documentation on label filtering

Closes #49651

See merge request gitlab-org/gitlab-ce!30741

Update dependency @gitlab/ui to ^5.9.0

See merge request gitlab-org/gitlab-ce!31153

The GitLab UI update changed the spinner selector from `spinner` to
`gl-spinner`, so we need to update it, so that our tests won't fail.

Extract Auto DevOps deploy functions in a base image

Closes #50286

See merge request gitlab-org/gitlab-ce!30404

Adds event enum column to DesignsVersions join table

See merge request gitlab-org/gitlab-ce!30745

Support indentation in the markdown editor

Closes #25070

See merge request gitlab-org/gitlab-ce!28914

It will be hooked up to the markdown editor later

Ensure Warden triggers after_authentication callback

See merge request gitlab-org/gitlab-ce!31138

By not triggering the callback:
- ActiveSession lookup keys are not cleaned
- Devise also misses its hook related to session cleanup

CE port of "Stablize editing scope label spec - retry if dropdown is not visible"

See merge request gitlab-org/gitlab-ce!31145

Respect alt email when sending group access notifications

See merge request gitlab-org/gitlab-ce!31089

When sending access granted/rejected emails we should also respect
custom emails set for groups/sub-groups

Feature test for gfm embedding metrics

See merge request gitlab-org/gitlab-ce!30621

Add points how to prepare for database reviews

Closes #65126

See merge request gitlab-org/gitlab-ce!31158

Using the sed script from
https://gitlab.com/gitlab-org/gitlab-ce/issues/59758

CI Docs update for Marketing

See merge request gitlab-org/gitlab-ce!30440

Update README.md - add CTA to watch Mastering CI/CD webcast and 5 teams that made the switch to GitLab CI/CD article

Add docs for template field in prometheus alerts

See merge request gitlab-org/gitlab-ce!30900