Piuparts fails on salsa-ci while it successed on piuparts.d.o (caused by --hard-links)

The piuparts tests for libnss-sssd 2.7.3-2 fail on salsa-ci [1] but succeed on piuparts.d.o [2].

A possible reason for this discrepancy is the fact that on salsa-ci piuparts reuses the same chroot because of the --hard-link parameter [3].

Maybe the (undetected) dirty state of a previous run interacts with libnss-sssd's maintscripts in a way that is undetected by more isolated piuparts tests and makes the piutests fail.

[1] https://salsa.debian.org/sssd-team/sssd/-/jobs/2907269
[2] https://piuparts.debian.org/sid/pass/libnss-sss_2.7.3-2.log
[3] https://salsa.debian.org/salsa-ci-team/pipeline/-/blob/7c0ac0b1/salsa-ci.yml#L606