Optimize DB indexes for ES indexing of notes

See merge request gitlab-org/gitlab-ce!31846

Expire project caches once per push instead of once per ref

Closes #52046

See merge request gitlab-org/gitlab-ce!31876

Previously `ProjectCacheWorker` would be scheduled once per ref, which
would generate unnecessary I/O and load on Sidekiq, especially if many
tags or branches were pushed at once. `ProjectCacheWorker` would expire
three items:

1. Repository size: This only needs to be updated once per push.
2. Commit count: This only needs to be updated if the default branch
   is updated.
3. Project method caches: This only needs to be updated if the default
   branch changes, but only if certain files change (e.g. README,
   CHANGELOG, etc.).

Because the third item requires looking at the actual changes in the
commit deltas, we schedule one `ProjectCacheWorker` to handle the first
two cases, and schedule a separate `ProjectCacheWorker` for the third
case if it is needed. As a result, this brings down the number of
`ProjectCacheWorker` jobs from N to 2.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/52046

Fix Arel deprecation warning in clusters_hierarchy

See merge request gitlab-org/gitlab-ce!31916

To index notes, we exclude system notes and use `find_in_batches` to
load them in batches for submission to the ES bulk import API.
These queries often result in DB timeouts because the usage of
`ORDER BY id` results in the `notes_pkey` index being used.

This adds an optimized partial index, and removes the unused index
`index_notes_on_noteable_type` which is already covered for our
usage by the existing `index_notes_on_noteable_id_and_noteable_type`.

Newer versions of PostgreSQL (at least 11) are smarter about this and
use `index_notes_on_project_id_and_noteable_type` instead, so we might
be able to remove the partial index again in the future.

Remove Security Dashboard feature flag

See merge request gitlab-org/gitlab-ce!31820

This removes the group_overview_security_dashboard feature flag

As mentioned in https://github.com/rails/rails/pull/29619, this removes
this warning message:

```
Delegating join_sources to arel is deprecated and will be removed in
Rails 6.0. (called from project_clusters_base_query at
app/models/clusters/clusters_hierarchy.rb:62)
```

Part of https://gitlab.com/gitlab-org/gitlab-ce/issues/61451

Quarantining add_file_template_spec

See merge request gitlab-org/gitlab-ce!31908

Issue - https://gitlab.com/gitlab-org/quality/nightly/issues/127

Generate shareable link for specific metric charts

See merge request gitlab-org/gitlab-ce!31339

Adds a clipboard button to the metrics dashboard, that allows
copying a link to an individual chart.

Add `needs:` CI config option CE

Closes gitlab-ee#12334

See merge request gitlab-org/gitlab-ce!31346

fix handling of empty ref_name parameter string in commits api

Closes #64745

See merge request gitlab-org/gitlab-ce!31687

Removed duplicate Live preview entry for MR docs

See merge request gitlab-org/gitlab-ce!31763

Doc: sync ES updates

See merge request gitlab-org/gitlab-ce!31883

Expose finished_at for the Deployment entity

See merge request gitlab-org/gitlab-ce!31808

Merge branch '47003-user-onboarding-replace-current-email-confirmation-flow-with-a-soft-email-confirmation-flow' into 'master'

Soft email confirmation flow

Closes #47003

See merge request gitlab-org/gitlab-ce!31245

Add docs for rate limiter on raw endpoints

See merge request gitlab-org/gitlab-ce!31723

The section was included on security/raw_limits and on the admin area
settings.

Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/48717

Adjust headers in /university

See merge request gitlab-org/gitlab-ce!31702

Update docs style for code blocks

Closes #65373

See merge request gitlab-org/gitlab-ce!31297

Clarify rules for code blocks, including spaces
above and below, and to use tilde when code blocks
contain triple backticks

Fix quarantined spec by waiting for requests

Closes #65329

See merge request gitlab-org/gitlab-ce!31862

Resolve "Web IDE uncommitted files use wrong icon in tree"

Closes #61335

See merge request gitlab-org/gitlab-ce!31560

- Uses vue-test-utils
- More complete coverage with parameterized tests

Document cleanup of feature flag after deploy

See merge request gitlab-org/gitlab-ce!31893

Enable DAG support by default

Closes #65457

See merge request gitlab-org/gitlab-ce!31814

Don't use go mod vendor

See merge request gitlab-org/gitlab-ce!31721

[Backport] Add feature specs for multiple issue boards for groups

See merge request gitlab-org/gitlab-ce!31481

Add feature specs for multiple issue boards for groups

Add key unbinds to DiscussionKeyboardNavigator

See merge request gitlab-org/gitlab-ce!31857

Add a note about the lack of arm64 support

See merge request gitlab-org/gitlab-ce!31887

Document option to set Security Dashboard as default view for groups

See merge request gitlab-org/gitlab-ce!31795

Revert adding productivity analytics docs

See merge request gitlab-org/gitlab-ce!31848