Make key4hep image compatible with apptainer

[kkrizka]

• Add building using GitLab and GitHub CIs.
• Do not use GCC 12 on Alma9 as it causes problems compiling whizard.
• Two setup scripts are available. The idea is that setup_mucoll.sh provides all necessary software for MuColl work.
  • /opt/setup_mucoll.sh: Setups the environment through a dump of the envrionment.
  • /opt/setup_spack.sh: Setups the spack environment.
• Readd a mucoll user for docker users.
• The build scripts have an optional environmental variable DOCKER to define the docker command (ie: for podman users).
• Port changes to CentOS8 image.