fix(CI): Bump psalm error level to 3

Signed-off-by: Joas Schilling <coding@schilljs.com>

psalm.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <psalm
 	errorBaseline="tests/psalm-baseline.xml"
-	errorLevel="5"
+	errorLevel="3"
 	findUnusedBaselineEntry="true"
 	findUnusedCode="false"
 	resolveFromConfigFile="true"