Bump PHPStan to the max level

WouterSioen · WouterSioen · commit f0300e0f00e5 · 2021-10-28T19:38:23.000+02:00
diff --git a/phpstan.neon b/phpstan.neon
@@ -1,5 +1,5 @@
 parameters:
-    level: 7
+    level: max
     paths:
         - src
         - tests
