Return 204 on all DELETE endpoints

Closes #20429

See merge request !9397

Clarify when to create EE compatibility MR in code review process

See merge request !9575

Only create unmergeable todos once

Closes #28555

See merge request !9513

Fix migration without DOWNTIME clause specified

See merge request !9571

Make RuboCop happy

See merge request !9554

Add button to create issue for failing build

Closes #25920

See merge request !9391

Fix inline comment images by removing wrapper #20890

Closes #20890

See merge request !5804

Fix broken dev environment in master

See merge request !9557

Keep consistent in handling indexOf results

Closes #28723

See merge request !9531

Add development fixtures for nested groups

See merge request !9553

Replace setInterval with setTimeout to prevent highly frequent requests

Closes #28212

See merge request !9271

[ci skip]

Fix #27840 - Improve the search bar experience on mobile

Closes #27840

See merge request !9280

[ci skip]

Removed jQuery UI draggable

See merge request !8582

Fix webpack dev server when behind proxy

See merge request !9543

[ci skip]

Minor refactoring of Uploaders

See merge request !9490

Align last column buttons with new environment button

Closes #28753

See merge request !9551

Updates SSH key title after pasting key

Closes #28436

See merge request !9481

Add Mock CI service/integration

See merge request !9250

Fixed alignment of RSS button on activity pages

Closes #28572

See merge request !9478

Improved the diff comment button UX

Closes #27543

See merge request !9448

Pipelines tables UI improvements

Closes #28383, #26611, #21788, #27048, and #27828

See merge request !9442

Add runner version to /admin/runners view

See merge request !8733

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Previously it was listening for focusout, it now listens for blur &
paste events

Closes #28436

Make nested groups deletion synchronous to avoid potential race

See merge request !9288