Update mediawiki/mediawiki-codesniffer requirement from 41.0.0 to 42.0.0

Updates the requirements on [mediawiki/mediawiki-codesniffer](https://github.com/wikimedia/mediawiki-tools-codesniffer) to permit the latest version.
- [Changelog](https://github.com/wikimedia/mediawiki-tools-codesniffer/blob/master/HISTORY.md)
- [Commits](wikimedia/mediawiki-tools-codesniffer@v41.0.0...v42.0.0)

---
updated-dependencies:
- dependency-name: mediawiki/mediawiki-codesniffer
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

composer.json

@@ -2,7 +2,7 @@
   "name": "femiwiki/discord-notifications",
   "description": "Sends Discord notifications for selected actions that have occurred in your MediaWiki sites.",
   "require-dev": {
-    "mediawiki/mediawiki-codesniffer": "41.0.0",
+    "mediawiki/mediawiki-codesniffer": "42.0.0",
     "mediawiki/mediawiki-phan-config": "0.12.0",
     "mediawiki/minus-x": "1.1.1",
     "php-parallel-lint/php-console-highlighter": "1.0.0",