Bump mediawiki/mediawiki-codesniffer from 38.0.0 to 39.0.0

Bumps [mediawiki/mediawiki-codesniffer](https://github.com/wikimedia/mediawiki-tools-codesniffer) from 38.0.0 to 39.0.0.
- [Release notes](https://github.com/wikimedia/mediawiki-tools-codesniffer/releases)
- [Changelog](https://github.com/wikimedia/mediawiki-tools-codesniffer/blob/master/HISTORY.md)
- [Commits](wikimedia/mediawiki-tools-codesniffer@v38.0.0...v39.0.0)

---
updated-dependencies:
- dependency-name: mediawiki/mediawiki-codesniffer
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

composer.json

@@ -6,7 +6,7 @@
   "license": "GPL-3.0+",
   "require-dev": {
     "mediawiki/mediawiki-phan-config": "^0.11.1",
-    "mediawiki/mediawiki-codesniffer": "38.0.0",
+    "mediawiki/mediawiki-codesniffer": "39.0.0",
     "php-parallel-lint/php-parallel-lint": "^1.3.2",
     "php-parallel-lint/php-console-highlighter": "^1.0.0",
     "mediawiki/minus-x": "^1.1"