Merge branch 'nelbacha-master-patch-81616' into 'master'

Cancel pending stuck jobs when they are pending AND stuck

Closes gitlab-com/support/docs#31

See merge request gitlab-org/gitlab!19622

doc/administration/troubleshooting/gitlab_rails_cheat_sheet.md

@@ -715,7 +715,7 @@ For more information, see the [confidential issue](../../user/project/issues/con
 
 ```ruby
 Ci::Pipeline.where(project_id: p.id).where(status: 'pending').count
-Ci::Pipeline.where(project_id: p.id).where(status: 'pending').each {|p| p.cancel}
+Ci::Pipeline.where(project_id: p.id).where(status: 'pending').each {|p| p.cancel if p.stuck?}
 Ci::Pipeline.where(project_id: p.id).where(status: 'pending').count
 ```