CI: run only tests-hg-stable in scheduled jobs
We'd like to have nightly pipeline runs, to know if all goes well with changes in Mercurial, but we don't want the jobs for Mercurial fixed versions to run.
All legacy (hg-git based) Projects have been automatically migrated to native with the upgrade of 2025-01-23
We'd like to have nightly pipeline runs, to know if all goes well with changes in Mercurial, but we don't want the jobs for Mercurial fixed versions to run.