Bug 31095: Remove GetDebarments from maxsuspensiondays.t

Bug 31095: Remove GetDebarments from maxsuspensiondays.t

This patch replaces GetDebarments in maxsuspensiondays.t with calls to
the restrictions accessor.

Test plan
1. Confirm t/db_dependent/Circulation/maxsuspensiondays.t passes prior
   to this patch
2. Confirm t/db_dependent/Circulation/maxsuspensiondays.t passes after
   this patch
3. Confirm no tests have been removed in this patch

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>