build(deps-dev): update mediawiki/mediawiki-phan-config requirement

Updates the requirements on [mediawiki/mediawiki-phan-config](https://github.com/wikimedia/mediawiki-tools-phan) to permit the latest version.
- [Release notes](https://github.com/wikimedia/mediawiki-tools-phan/releases)
- [Changelog](https://github.com/wikimedia/mediawiki-tools-phan/blob/master/HISTORY.md)
- [Commits](https://github.com/wikimedia/mediawiki-tools-phan/compare/0.12.0...0.12.1)

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

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

composer.json

@@ -29,7 +29,7 @@
 	},
 	"require-dev": {
 		"mediawiki/mediawiki-codesniffer": "41.0.0",
-		"mediawiki/mediawiki-phan-config": "0.12.0",
+		"mediawiki/mediawiki-phan-config": "0.12.1",
 		"mediawiki/minus-x": "1.1.1",
 		"php-parallel-lint/php-console-highlighter": "1.0.0",
 		"php-parallel-lint/php-parallel-lint": "1.3.2"