GH Actions: minor tweaks:
GH Actions: minor tweaks:

* Fix the description for two of the builds.
* Remove the PHPCompatibility build as this is already included in the PHPCS build.
    See: https://github.com/Dealerdirect/phpcodesniffer-composer-installer/blob/8bcaa7c245e3d2a6325f45aa94754e1d1b67d1a2/phpcs.xml.dist#L15-L16

DealerDirect/phpcodesniffer-composer-installer