Bug 31095: Remove GetDebarments from Koha::Patron::Debarments

Bug 31095: Remove GetDebarments from Koha::Patron::Debarments

This patch finally removes GetDebarments from the codebase.

Test plan
1. Confirm GetDebarments is no longer mentioned in the codebase. `git
   grep GetDebarments`
2. Confirm t/db_dependent/Patron/Borrower_Debarments.t continues to pass

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>
(cherry picked from commit 7c1ffd2b11501fdcedb8e7dd2e2838283c847ede)
Signed-off-by: Matt Blenkinsop <matt.blenkinsop@ptfs-europe.com>