Convert to GitlabCI

Gitlab CI pipeline failing on composer due to drush version.

See https://git.drupalcode.org/project/install_profile_generator/-/jobs/59833

Loading composer repositories with package information
Info from https://repo.packagist.org: #StandWithUkraine
Updating dependencies
Unable to find a compatible set of packages based on your non-dev requirements alone.
Your requirements can be resolved successfully when require-dev packages are present.
You may need to move packages from require-dev or some of their dependencies to require.
  Problem 1
    - Root composer.json requires drush/drush ^11, found drush/drush[12.1.2] but it does not match the constraint.

Moving issue to 3.0.x branch.

Tests currently failing for 3.0.x on gitlab because it currently requires drush ^9 || ^10 and Gitlab CI is installing 12.

See https://git.drupalcode.org/project/install_profile_generator/-/jobs/60315.