https://www.mediawiki.org/wiki/Extension:UserMerge
# Allows sysops to merge user A to user B and delete User A
- name: UserMerge
repo: https://github.com/wikimedia/mediawiki-extensions-UserMerge.git
version: "{{ mediawiki_default_branch }}"
config: |
$wgGroupPermissions['bureaucrat']['usermerge'] = true;