Bug 29086: (follow-up) Remove unrequired Koha::ArticleRequest::Status uses

Bug 29086: (follow-up) Remove unrequired Koha::ArticleRequest::Status uses

I noticed a couple places in which this library was included but not
used.

To test:
1. Apply this patch
2. Run:
   $ git grep 'Koha::ArticleRequest::Status'
=> SUCCESS: There aren't any calls to their defined constants in
Biblio.pm or Patrons.pm
3. Sign off :-D

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>