Setup PHP in GitHub Actions

GitHub action to set up PHP with extensions, php.ini configuration, coverage drivers, and various tools. Setup PHP with required extensions, php.ini configuration, code-coverage support and various tools like composer in GitHub Actions. This action gives you a cross-platform interface to set up the PHP environment you need to test your application. Refer to Usage section and examples to see how to use this. Refer to the self-hosted setup to use the action on self-hosted runners. Operating systems based on the above Ubuntu and Debian versions are also supported on best effort basis. If the requested PHP version is pre-installed, setup-PHP switches to it, otherwise it installs the PHP version. Specific versions of extensions available on PECL can be set up by suffixing the extension's name with the version. This is useful for installing old versions of extensions that support end-of-life PHP versions.