Merge branch '217418-deprecate-append-prepend-classes' into 'master'

Deprecate append/prepend utility classes

See merge request gitlab-org/gitlab!31679

app/assets/stylesheets/framework/common.scss

@@ -392,6 +392,10 @@ img.emoji {
 }
 
 /** COMMON CLASSES **/
+/**
+  🚨 Do not use these classes — they are deprecated and being removed. 🚨
+  See https://gitlab.com/gitlab-org/gitlab/-/issues/217418 for more details.
+**/
 .prepend-top-0 { margin-top: 0; }
 .prepend-top-2 { margin-top: 2px; }
 .prepend-top-4 { margin-top: $gl-padding-4; }

doc/development/fe_guide/style/scss.md

@@ -17,7 +17,7 @@ led by the [GitLab UI WG](https://gitlab.com/gitlab-com/www-gitlab-com/-/merge_r
 #### Where are utility classes defined?
 
 - [Bootstrap's Utility Classes](https://getbootstrap.com/docs/4.3/utilities/)
-- [`common.scss`](https://gitlab.com/gitlab-org/gitlab/blob/master/app/assets/stylesheets/framework/common.scss) (old)
+- [`common.scss`](https://gitlab.com/gitlab-org/gitlab/blob/master/app/assets/stylesheets/framework/common.scss) (old, many classes are now deprecated)
 - [`utilities.scss`](https://gitlab.com/gitlab-org/gitlab/blob/master/app/assets/stylesheets/utilities.scss) (new)
 
 #### Where should I put new utility classes?