phpstan only needs to react to relevant changes

.gitlab-ci.yml

@@ -236,7 +236,11 @@ phpstan:
   stage: analyse
   needs: [build-composer]
   rules:
-    - !reference [.definitions, php-changed]
+    changes:
+      - app/controllers/**/*.php
+      - lib/**/*.php
+      - tests/**/*.php
+
   variables:
     CACHE_LOCATION: $CACHE_DIR/phpstan
     PHPSTAN_CODE_QUALITY_REPORT: $REPORT_DIR/phpstan-codequality.json