Drop bullseye-backports from mirror

This was announced more than a year ago, but seems to have happened only
now.

[0] https://lists.debian.org/debian-backports-announce/2024/07/msg00000.html

Signed-off-by: Dr. Jens Harbott <harbott@osism.tech>
Change-Id: I3e2c0afed97f544b7f94b9f649f3aad7d24c355d

playbooks/roles/reprepro/files/debian/config/distributions

@@ -20,19 +20,6 @@ Contents: .gz
 Update: debian
 Log: /var/log/reprepro/debian-bullseye-updates.log
 
-Origin: Debian Backports
-Label: Debian Backports
-Codename: bullseye-backports
-NotAutomatic: yes
-ButAutomaticUpgrades: yes
-Description: OpenStack Debian Bullseye Backports mirror
-Architectures: amd64 arm64
-Components: main
-UDebComponents: main
-Contents: .gz
-Update: debian
-Log: /var/log/reprepro/debian-bullseye-backports.log
-
 
 Origin: Debian
 Label: Debian