Split [debian.sh] into multiple scripts inside a [debian] directory, adjusted references in other files to reflect changes

debian/contrib.sh

@@ -0,0 +1,36 @@
+#!/bin/bash
+set -euo pipefail
+
+source \
+	/etc/os-release
+
+
+cat << EOF | tee --append /etc/apt/sources.list.d/${VERSION_CODENAME}.sources &> /dev/null
+
+# ${VERSION_CODENAME^} Backports
+Enabled:		yes
+Types:			deb deb-src
+URIs:			http://deb.debian.org/debian/
+Suites:			${VERSION_CODENAME}-backports
+Components:		main non-free-firmware contrib
+Signed-By:		/usr/share/keyrings/debian-archive-keyring.gpg
+EOF
+
+cat << EOF | tee /etc/apt/preferences.d/backports.pref &> /dev/null
+Package:		*
+Pin:			release	n=${VERSION_CODENAME}*
+Pin-Priority:	990
+
+Package:		linux-*
+Pin:			release	n=${VERSION_CODENAME}-backports
+Pin-Priority:	-1
+EOF
+
+if [[ "${VERSION_CODENAME}" == 'bookworm' ]]; then
+	cat << EOF | tee --append /etc/apt/preferences.d/backports.pref &> /dev/null
+
+Package: /wayland/
+Pin: release n=${VERSION_CODENAME}-backports
+Pin-Priority: -1
+EOF
+fi