Update mediawiki/mediawiki-phan-config requirement from 0.14.0 to 0.15.0

Updates the requirements on [mediawiki/mediawiki-phan-config](https://github.com/wikimedia/mediawiki-tools-phan) to permit the latest version.
- [Changelog](https://github.com/wikimedia/mediawiki-tools-phan/blob/master/HISTORY.md)
- [Commits](wikimedia/mediawiki-tools-phan@0.14.0...0.15.0)

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

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

composer.json

@@ -41,7 +41,7 @@
 	},
 	"require-dev": {
 		"mediawiki/mediawiki-codesniffer": "45.0.0",
-		"mediawiki/mediawiki-phan-config": "0.14.0"
+		"mediawiki/mediawiki-phan-config": "0.15.0"
 	},
 	"extra": {
 		"branch-alias": {