Bug 36010: Fix Items/AutomaticItemModificationByAge.t failing since Bug 32029

Bug 36010: Fix Items/AutomaticItemModificationByAge.t failing since Bug 32029

UT is failing in jenkins.
Change to use biblio.copyrightdate instead of bilio.medium

Run prove t/db_dependent/Items/AutomaticItemModificationByAge.t

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit 2e6a2c3b5b6d0464215189e29954d06e5f6e236b)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>