Revert MattermostNotificationService and SlackNotificationService to MattermostS…

Closes #25889

See merge request !8240

Fix error 500 renaming group. Also added specs and changelog.

Closes #17922 and #23223

See merge request !8201

Fix cross-project references copy to include the project reference

Closes #25890

See merge request !8232

Rename projects with reserved path names

See merge request !8234

Use stable icon for Mattermost integration

See merge request !8252

Resolve "Labels are not consistent on all pages"

Closes #25951

See merge request !8256

Remove bottom border from Issuable titles

See merge request !8278

Add changelog entry for renaming API param

See merge request !8433

Fix project hooks params

Closes #26291

See merge request !8425

Gitlab::LDAP::Person uses LDAP attributes configuration

Closes #26290

See merge request !8418

Removes invalid html and unneeded CSS to prevent shaking in the pipelines tab

Closes #26278

See merge request !8411

API: extern_uid is a string

Closes #26227

See merge request !8404

Copy, don't move uploaded avatar files

Closes #26158

See merge request !8396

Add API route slack slash commands

Closes #25954

See merge request !8362

Fixed regression of note-headline-light where it was always placed on 2 lines, e…

See merge request !8348

fix left border in session tabs

Closes #24941

See merge request !8346

Fix unclear closing issue behaviour on Merge Request show page

Closes #26152

See merge request !8345

Fix 500 error when visit group from admin area if group name contains dot

See merge request !8342

Fix GFM dropdown not showing at beginning of new lines

Closes #26145

See merge request !8338

Fix grammar error in text about mentioned issues

See merge request !8337

Only limit container width on issues & MRs within fixed-width container

Closes #25907

See merge request !8330

Cache project authorizations even when user has access to zero projects

Closes #26126

See merge request !8327

[ci skip]

Order only for latest_successful_for

See merge request !8301

This reverts commit bdcdf454.

This reverts commit a18ad6cf.

[ci skip]

Resolve "Mini pipeline graph dropdown looks weird on Safari and hover does not work on firefox"

Closes #26018, #26004, and #26002

See merge request !8282

Order only for latest_successful_for

See merge request !8301

Fix single team selection

See merge request !8251

Hide Scroll Top button for failed Build page

Closes #26040

See merge request !8295

Fix line breaking in nodes of the pipeline graph in firefox

Closes #26026

See merge request !8292

Fix text overflow

Closes #25930

See merge request !8273

Added changelog for MR !8322

See merge request !8325

Disable timeout while removing services

Closes #25976

See merge request !8322

Merge branch '25931-gitlab-merge-request-view-crash-when-commiting-a-js-sourcemap-file' into 'master'

Resolve "Gitlab merge request view crash when commiting a js sourcemap file"

Closes #25931

See merge request !8310

fixes confidential warning alignment on comment box

Closes #26038

See merge request !8293

Rename "autodeploy" to "auto deploy"

Closes #25999

See merge request !8289

Fixed error with GFM autocomplete when no data exists

See merge request !8288