Update git submodules
- Update extensions/CodeEditor from branch 'REL1_39' to bbf82044002633d5854abf26542027947b969bd0
- Merge "build: Update MediaWiki requirement to 1.39.0" into REL1_39
- build: Update MediaWiki requirement to 1.39.0
Change-Id: If0bfede1a99bca05670f78901c6e49026e1ef7db