fix(package): bump deps, update to phpunit-12, introduce phpstan.baseline

... and minor codestyle fixes

Author: rtm-ctrlz

phpunit.xml.dist

@@ -4,10 +4,11 @@
         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/12.0/phpunit.xsd"
         backupGlobals="true"
         cacheDirectory="./test/caches/phpunit"
+
 >
     <source>
         <include>
-            <directory suffix=".php">./src</directory>
+            <directory>./src</directory>
         </include>
     </source>
     <testsuites>