build: allow quiqqer/fontawesome in version 6

See merge request !10

This commit removes the phpunit-php8.1, phpunit-php8.2 and phpunit-php8.3 blocks from
.gitlab-ci.yml to allow PHPUnit tests to run on PHP 8.1, 8.2, and 8.3 in the pipeline.

Next

See merge request !6

ci: include quiqqer-package-bundle component

See merge request !5

refactor: set the width and height css properties to 'auto' to avoid images being displayed at a reduced size.