chore: exclude frontend.asset.php from phpcs checks

Author: ajaydsouza

phpcs.xml.dist

@@ -9,6 +9,7 @@
 	<exclude-pattern>*/tests/*</exclude-pattern>
 	<exclude-pattern>*/index.php</exclude-pattern>
 	<exclude-pattern>*/index.asset.php</exclude-pattern>
+	<exclude-pattern>*/frontend.asset.php</exclude-pattern>
 	<exclude-pattern>*/freemius/*</exclude-pattern>
 	<exclude-pattern>*/.playground/*</exclude-pattern>