Fix extra emails for custom notifications

Closes #56861

See merge request gitlab-org/gitlab-ce!25607

Using custom_action and recipient filtering

Add more generic filtering to user_ids_notifiable_on

Add changelog entry

Remove commented class

Method is no longer needed

Overloading no longer required

Filter by action just in case of custom notification level

Add participant check

Fix unexpected extra notification mails

Using custom_action and recipient filtering

Add more generic filtering to user_ids_notifiable_on

Add changelog entry

Remove commented class

Method is no longer needed

Overloading no longer required

Filter by action just in case of custom notification level

Fix comment

Add repond_to? checks

Reverted custom_action filtering

Enhanced output of should_email helper

Changed :watch to :participating for custom notifiable users

Change spec variable name

Enhanced participating check

These conditions are no longer needed

Fix custom notification handling for participating type

Participating level should include maintainers

Fixed add_guest notification

Fix successful pipeline notification

Refactoring: Use maintainer? method on team instead

Add spec for new_issue: true for a custom group setting
which should have lower prio than an available project setting

Clean up specs

Add note about MR Pipeline Runner version

Closes gitlab-ee#11122

See merge request gitlab-org/gitlab-ce!27330

Docs: Fix typo on DB migration

See merge request gitlab-org/gitlab-ce!27435

Update external prometheus config

See merge request gitlab-org/gitlab-ce!27439

Removes EE diffs for dropdown_value_collapsed.vue

Closes gitlab-ee#10083

See merge request gitlab-org/gitlab-ce!27367

Backport of "Resolves EE differences for project_new.js"

See merge request gitlab-org/gitlab-ce!27285

Fix typo

See merge request gitlab-org/gitlab-ce!27443

Fix stylelint warnings in related_items_list.scss

See merge request gitlab-org/gitlab-ce!27432

Fix stylelint rules in boards.scss

Closes #59895

See merge request gitlab-org/gitlab-ce!27313

Removes ifEE example for JS code.

See merge request gitlab-org/gitlab-ce!27408

Add help texts to K8 form fields

Closes #59275

See merge request gitlab-org/gitlab-ce!27274

Fix logic in Api::Internal test

See merge request gitlab-org/gitlab-ce!27193

Allow extra args for helm in Auto-DevOps

See merge request gitlab-org/gitlab-ce!26838

[CE backport] Fix no assignee text in sidebar_spec

See merge request gitlab-org/gitlab-ce!27444

The intention of this test is to ensure that the service class
MergeRequests::PushOptionsHandlerService does not run when the
:mr_push_options feature flag is disabled.

This test was passing, however was not testing what it was supposed to
be!

For one, setting Feature.disable(:feature) in the test does not disable
the feature, as rspec config in spec_helper stubs Feature to make all
features enabled:

https://gitlab.com/gitlab-org/gitlab-ce/commit/3ee48e422defaedd69946c607bd8d3672e510375

So the feature was still enabled in the test.

But this test wasn't failing because unfortunately I had put:

```
expect(MergeRequests::PushOptionsHandlerService).to receive(:new)
```

instead of not_to!

This meant that the `.new` method was being stubbed, so the service
class did not create a MergeRequest, which satisfied the second
expectation.

```
expect(MergeRequests::PushOptionsHandlerService).to receive(:new)
```

Updated to include missing metrics:
    * GitLab Workhorse
    * Nginx
    * Sidekiq

Set correct timestamps when creating past issues

Closes #58361

See merge request gitlab-org/gitlab-ce!27406

`None` for assignees

Closes #60599

See merge request gitlab-org/gitlab-ce!27419

Update assignees_spec.js

Update sidebar_spec.rb

Update issues_spec.rb

Test using Git 2.21

See merge request gitlab-org/gitlab-ce!27418

Resolve "Karma failing with MrWidgetAlertMessage when helpPath is provided  Maximum call stack size exceeded"

Closes #60605

See merge request gitlab-org/gitlab-ce!27429

This commit rearranges the styles in related_items_list
to adhere to stylelint's warnings. It also adds some
utility classes where applicable

Docs: CI/CD intro - add new illustration + description

See merge request gitlab-org/gitlab-ce!27278

Link to resource label events API

See merge request gitlab-org/gitlab-ce!27412

Create frontend FAQ (documentation)

See merge request gitlab-org/gitlab-ce!26372