Merge branch 'fix-bug-template' into 'master'

Rename behaviour to behavior in bug issue template for consistency

## What does this MR do?
Rename `behaviour` to` behavior` in bug issue template for consistency

## Are there points in the code the reviewer needs to double check?
None

## Why was this MR needed?
Consistency 👍🏻 

## Screenshots (if relevant)
None

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- Tests
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?
Closes #21789

See merge request !6166

.gitlab/issue_templates/Bug.md

@@ -10,7 +10,7 @@
 
 (What you should see instead)
 
-### Actual behaviour
+### Actual behavior
 
 (What actually happens)
 

CHANGELOG

@@ -16,6 +16,7 @@ v 8.12.0 (unreleased)
   - Set path for all JavaScript cookies to honor GitLab's subdirectory setting !5627 (Mike Greiling)
   - Fix bug where pagination is still displayed despite all todos marked as done (ClemMakesApps)
   - Center build stage columns in pipeline overview (ClemMakesApps)
+  - Rename behaviour to behavior in bug issue template for consistency (ClemMakesApps)
   - Shorten task status phrase (ClemMakesApps)
   - Add hover color to emoji icon (ClemMakesApps)
   - Fix branches page dropdown sort alignment (ClemMakesApps)