Merge branch 'phpstan' into 'dev'

# Conflicts:
#   .gitlab-ci.yml

phpstan.dist.neon

 parameters:
-    level: 6
+    level: 9
     paths:
         - src
+        - tests
     bootstrapFiles:
         - tests/phpstan-bootstrap.php

src/QUI/Test/EventHandler.php

@@ -23,9 +23,7 @@ class EventHandler
      */
     public static function onUserGetAvatar(UserInterfaces $User)
     {
-        // random comment
-        return false;
-
+        // some random comment
         return new ExternalImage(
             'https://api.adorable.io/avatars/200/abott@adorable.png'
         );
@@ -34,7 +32,7 @@ public static function onUserGetAvatar(UserInterfaces $User)
     /**
      * @param Package $Package
      */
-    public static function onInstall(Package $Package)
+    public static function onInstall(Package $Package): void
     {
         Log::writeRecursive('ON INSTALL');
         Log::writeRecursive($Package->getName());

src/QUI/Test/Test.php

@@ -9,7 +9,7 @@
 
 class Test
 {
-    public static function onUserGetAvatar(UserInterfaces $User)
+    public static function onUserGetAvatar(UserInterfaces $User): bool
     {
         // a comment (edited again)
         return false;