Have GitLab Runner package installation ignore skel when creating user home directory
We allow users to install GitLab Runner using a package repository, which creates a home directory and has the defaults skeleton directory specified in the machine. Debian buster breaks this because of the .bash_logout (issue #4449 (closed)). In !1523 (closed) we added a flag
GITLAB_RUNNER_DISABLE_SKEL which allows user to remove the skel and have the home directory empty for the
This flag is turned off by default for now to prevent breaking change.