Add latest changes from gitlab-org/gitlab@master

changelogs/unreleased/CauhxMilloy-gitlab-addStartEndMarkersForTagsSearch.yml

----
-title: Adding support for searching tags using '^' and '$'
-merge_request: 19435
-author: Cauhx Milloy
-type: added

changelogs/unreleased/Remove-IIFEs-from-image_file-js.yml

----
-title: Removed IIFEs from image_file.js
-merge_request: 19548
-author: nuwe1
-type: other

changelogs/unreleased/Remove-IIFEs-from-network-js.yml

----
-title: Removed IIFEs from network.js file
-merge_request: 19254
-author: nuwe1
-type: other

changelogs/unreleased/Update-boards-components-board_form-vue.yml

----
-title: Remove all reference to BoardService in board_form.vue
-merge_request: 20158
-author: nuwe1
-type: other

changelogs/unreleased/Update-boards-components-models-index-vue.yml

----
-title: Remove all references to BoardsService in index.vue
-merge_request: 20152
-author: nuwe1
-type: other

changelogs/unreleased/Update-boards_selector-vue-to-use-boardsStore.yml

----
-title: remove all references of BoardService in boards_selector.vue
-merge_request: 20147
-author: nuwe1
-type: other

changelogs/unreleased/ab-projects-api-indexes-authenticated.yml

----
-title: Add index for authenticated requests to projects API default endpoint
-merge_request: 19993
-author:
-type: performance

changelogs/unreleased/ab-projects-api-indexes.yml

----
-title: Add index for unauthenticated requests to projects API default endpoint
-merge_request: 19989
-author:
-type: performance

changelogs/unreleased/ab-projects-id-filter.yml

----
-title: Add id_before, id_after filter param to projects API
-merge_request: 19949
-author:
-type: added

changelogs/unreleased/add-dead-jobs-to-api-sidekiq-metrics.yml

----
-title: Add dead jobs to Sidekiq metrics API
-merge_request: 19350
-author: Marco Peterseil
-type: added

changelogs/unreleased/add-default-plan.yml

----
-title: Create explicit Default and Free plans
-merge_request: 19033
-author:
-type: other

changelogs/unreleased/add-inheritable-mixin.yml

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-title: Make `Job`, `Bridge` and `Default` inheritable
-merge_request: 18867
-author:
-type: added

changelogs/unreleased/add-missing-bottom-padding-in-settings.yml

----
-title: Add missing bottom padding in CI/CD settings
-merge_request: 19284
-author: George Tsiolis
-type: fixed

changelogs/unreleased/add-pendo-snippet.yml

----
-title: Adds Application Settings and ui settings in the integration admin area for Pendo
-merge_request: 15086
-author:
-type: added

changelogs/unreleased/add-rails-parser-for-new-cs-report-format.yml

----
-title: Handle new Container Scanning report format
-merge_request: 19123
-author:
-type: changed

changelogs/unreleased/add-slack-slash-command-issue-comment.yml

----
-title: Add a Slack slash command to add a comment to an issue
-merge_request: 18946
-author:
-type: added

changelogs/unreleased/add-snowplow-iglu-registry-application-setting.yml

----
-title: Add ApplicationSetting for snowplow_iglu_registry_url
-merge_request: 18449
-author:
-type: added

changelogs/unreleased/ak-add-elastic-cluster-app.yml

-title: Create table for elastic stack.
-merge_request: 18015
-author:
-type: added

changelogs/unreleased/ak-fix-undefined-value.yml

----
-title: Fix uninitialized constant SystemDashboardService
-merge_request: 19453
-author:
-type: fixed

changelogs/unreleased/allow-adding-requests-to-performance-bar-manually.yml

----
-title: Allow adding requests to performance bar manually
-merge_request: 18464
-author:
-type: other