fix: add phpstan-bootstrap.php PHPCS exclusion

Author: ajaydsouza

phpcs.xml.dist

@@ -10,6 +10,7 @@
 	<exclude-pattern>*/index.php</exclude-pattern>
 	<exclude-pattern>*/index.asset.php</exclude-pattern>
 	<exclude-pattern>*/frontend.asset.php</exclude-pattern>
+	<exclude-pattern>*/phpstan-bootstrap.php</exclude-pattern>
 	<exclude-pattern>*/freemius/*</exclude-pattern>
 	<exclude-pattern>*/.playground/*</exclude-pattern>