GitLab supports PostgreSQL only since https://gitlab.com/gitlab-org/gitlab-foss/merge_requests/29790.

Follows up https://gitlab.com/gitlab-org/gitlab-foss/merge_requests/29608,
https://gitlab.com/gitlab-org/gitlab/merge_requests/14645,
https://gitlab.com/gitlab-org/gitlab/commit/988dc80585c6e52970e94f22dff6bc1e4c786e9e,
https://gitlab.com/gitlab-org/gitlab/merge_requests/14239,
https://gitlab.com/gitlab-org/gitlab/merge_requests/20319

/cc @nick.thomas

Programmatically document column ignores

See merge request gitlab-org/gitlab!19963

Makes the security dashboard empty state a scoped slot

See merge request gitlab-org/gitlab!18382

- Defaults to a generic empty state message.
- Set explicit messages for:
- - Group Dashboard
- - Project Dashboard
- - Pipeline Dashboard

Limit the merge request target branch autocompletion action to group or project scope

See merge request gitlab-org/gitlab!20933

Improve .groups_user_can_read_epics performance

See merge request gitlab-org/gitlab!20833

Refactor environment table titles and spacing

See merge request gitlab-org/gitlab!20769

Add dependency scanning flag

See merge request gitlab-org/gitlab!20743

Resolve "Docs feedback: Need to document required permissions"

Closes #35933

See merge request gitlab-org/gitlab!20861

Allow intra-project MR dependencies

Closes #34735

See merge request gitlab-org/gitlab!20858

Link correct template in the Maintenance policy

See merge request gitlab-org/gitlab!20914

Edit backup section in patch_versions documentation

See merge request gitlab-org/gitlab!20609

(cherry picked from commit b0e531b7836ae8ce149e2d57384a071131f625eb)

Update upgrade path recommendations

See merge request gitlab-org/gitlab!20878

Add clarification suggesting 11.11.x -> 12.0.x

Include create_personal_snippet ability for new/create snippet actions

See merge request gitlab-org/gitlab!20838

In this MR we check the create_personal_snippet ability
whenever we show the button to create a new snippet. It
also changes the place the ability is created to avoid
scoping it inside a Snippet.

Docs: add badge to feature available for admins only

See merge request gitlab-org/gitlab!20774

Marginalia inclusion

Closes #27857

See merge request gitlab-org/gitlab!19759

Combine frontend style guides - docs

Closes gitlab-org/frontend/general#25

See merge request gitlab-org/gitlab!20969

This is part of a wider effort to consolidate
frontend development guides. Issue here:
https://gitlab.com/gitlab-org/frontend/general/issues/25

Keyset pagination for `Project` based on `id` column

See merge request gitlab-org/gitlab!19623

Fix check for existing ES limited indexing IDs

See merge request gitlab-org/gitlab!20866

Delete any stale deploy access levels  by group

See merge request gitlab-org/gitlab!20689

Creating a test for `Contribution Analytics`

Closes gitlab-org/quality/testcases#121

See merge request gitlab-org/gitlab!19960

Reset all the commits into one collective commit that encompasses all
the work done.

Simplify test to avoid flakiness

Closes #37369

See merge request gitlab-org/gitlab!20931

Cache Repository#ancestor? on two levels

See merge request gitlab-org/gitlab!20958

We sometimes call this multiple times per request, and we also call
this from a polled endpoint. So caching it on both levels could
speed up a bunch of those polled requests

Update sitespeed to 11.2.0

See merge request gitlab-org/gitlab!20561

Use explicitly tracked deployments for MR widgets

See merge request gitlab-org/gitlab!20066

Move the `post-test` stage closer to the `test` stage

Closes #37375

See merge request gitlab-org/gitlab!20796

Correct redundant language

See merge request gitlab-org/gitlab!20965