build: Updating mediawiki/mediawiki-codesniffer to 43.0.0

Change-Id: I6438c0cc1f1ce53d7db21eff8e75a94183d543c7

composer.json

@@ -1,6 +1,6 @@
 {
 	"require-dev": {
-		"mediawiki/mediawiki-codesniffer": "41.0.0",
+		"mediawiki/mediawiki-codesniffer": "43.0.0",
 		"mediawiki/mediawiki-phan-config": "0.14.0",
 		"mediawiki/minus-x": "1.1.1",
 		"php-parallel-lint/php-console-highlighter": "1.0.0",
@@ -18,5 +18,10 @@
 		],
 		"phan": "phan -d . --long-progress-bar",
 		"phpcs": "phpcs -sp --cache"
+	},
+	"config": {
+		"allow-plugins": {
+			"dealerdirect/phpcodesniffer-composer-installer": true
+		}
 	}
 }