Replication slots are not supported in Aurora. Attempting to check
the lag results in the message:

```
ActiveRecord::StatementInvalid: PG::FeatureNotSupported: ERROR:
Replication slots are currently not supported in Aurora : SELECT
pg_xlog_location_diff(pg_current_xlog_insert_location(),
restart_lsn)::...
```

To avoid breaking support for background migrations in Aurora, we just
disable the check if we encounter this error.

This change also now checks whether there are any replication slots
present in the primary before checking the replication lag.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/52176

Use our own docker image for helm install pods

See merge request gitlab-org/gitlab-ce!22778

This will reduce dependencies and failure points during installation. It
will also reduce security risks from untrusted dependencies being able
to effect all our users

Add email for milestone change

Closes #51520

See merge request gitlab-org/gitlab-ce!22279

Incorporates Kubernetes Namespace into Cluster's flow

See merge request gitlab-org/gitlab-ce!22011

Don't log fabricate args

See merge request gitlab-org/gitlab-ce!22753

Prevents logging of sensitive data

Fixes a migration that causes error on some legacy DBs

Closes #46862

See merge request gitlab-org/gitlab-ce!22761

Cannot add label to issue from board

Closes #51620

See merge request gitlab-org/gitlab-ce!22475

Top level clusters controller

See merge request gitlab-org/gitlab-ce!22438

Adds pagination to pipelines table in merge request & commit page

Closes #28249

See merge request gitlab-org/gitlab-ce!22696

Add scheduled flag to job entity

See merge request gitlab-org/gitlab-ce!22710

TokenAuthenticatable allows non-unique tokens

See merge request gitlab-org/gitlab-ce!22748

Remove ci_enable_scheduled_build feature flag

Closes #52183

See merge request gitlab-org/gitlab-ce!22742

Significantly cut memory and SQL queries when reloading diffs

See merge request gitlab-org/gitlab-ce!22725

Resolve "Links in tabs of the labels index pages ends with `.html`"

Closes #52548

See merge request gitlab-org/gitlab-ce!22716

Add index to find stuck merge requests.

Closes #45608

See merge request gitlab-org/gitlab-ce!22749

Remove gitlab-ui's progress bar from global

See merge request gitlab-org/gitlab-ce!22705

[master] Security kubeclient ssrf

See merge request gitlab/gitlabhq!2575

Change HELM_HOST in Auto-DevOps to work behind proxy

See merge request gitlab-org/gitlab-ce!22596

Looks like there are some legacy GitLab databases that have a NOT NULL
constraint for the `created_at` and `updated` fields.

This change fixes the migration by adding a default value to those
columns and I think we always should have it in mind when inserting DB
records through raw SQL.

Link Bitbucket Server from import index page

See merge request gitlab-org/gitlab-ce!22752

Fix "rails g migration" not always using migration templates

Closes #52651

See merge request gitlab-org/gitlab-ce!22592

Replace tooltip in markdown component with gl-tooltip

See merge request gitlab-org/gitlab-ce!21989

Reduce merge conflicts in the User model

See merge request gitlab-org/gitlab-ce!22697

Reserve more RAM for master process in Puma

See merge request gitlab-org/gitlab-ce!22741

To reduce the number of abstract methods, use polymorphic_paths for
collection routes. Unfortunately for member routes, polymorphic_paths
does not support namespaced classes, so still continue to override
methods.

We introduced hidden_clusterable_fields in this MR but it is no longer
needed as we have gone back to nested resource routes which should
provide the params such as `project_id`.

Also add missing interface in abstract class.

Use CI_COMMIT_REF_SLUG when building assets image

See merge request gitlab-org/gitlab-ce!22756

* Using CI_COMMIT_REF_NAME fails when the branch or tag contains special
characters

CE backport from  Added a search bar to `Admin > Geo > Projects`

See merge request gitlab-org/gitlab-ce!22747

Use merge_db_schema for db/schema.rb conflicts

See merge request gitlab-org/gitlab-ce!22692