.gitlab-ci: Remove tags no longer provided by gitlab.com

.gitlab-ci: Remove tags no longer provided by gitlab.com

GitLab.com removed a number of tags from their hosted
runners and this meant our CI was being redirected to
our private runners at a larger cost to the Samba Team.

The new infrastructure is much larger than when we last
selected runners so we can just use the default, even for
the code coverage build.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15638

Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
Autobuild-User(master): Stefan Metzmacher <metze@samba.org>
Autobuild-Date(master): Tue May  7 13:40:55 UTC 2024 on atb-devel-224