Changes

debian-bookworm-build(-arm): new docker containers

Create debian bookworm (12) based containers for building all Osmocom
projects in master/gerrit/ttcn3 jenkins jobs.

This is a combination of debian-bullseye-build (ttcn3) and
debian-bullseye-jenkins(-arm) (master/gerrit), which were used for this
purpose but had several differences. Combining them solves the
following problems:
 * The naming was confusing, as both the -jenkins and -build containers
   were used in jenkins and were used to build the Osmocom stack.
 * This lead to adding the dependencies to the wrong containers / not
   adding them to both containers.
 * Now we are sure that if a program builds from source in the master
   and gerrit verifications, it will also build in the ttcn3 jobs.

Other notable changes from the debian 11 containers:
 * Python2 is finally gone (OS#5950, for the few projects that still
   need it like openbsc, I'll use debian 11 for the jenkins jobs)
 * Removed osc and git-buildpackage, now that OBS package building is
   done in different docker containers (see osmo-ci/scripts/obs)
 * Combined multiple RUN commands into one as they the image build
   down, used set -x to display what commands run exactly
 * Use UID variable instead of hardcoding 1000
 * Optimized order of commands, so e.g. the LLVM for Arm that we will
   rarely change gets installed/cached before the big list of apt pkgs
 * Replaced old git.osmocom.org urls
 * Removed apt-get upgrade; the base image will get upgraded from time
   to time, no need to upgrade within the image
 * Add --depth=1 option to git clones and remove temporary git clones
 * Removed generating locales code, it was only done by one of the two
   images and I couldn't find in the git log why we would need this (if
   we do need it we can add it back later)

The following patches add more debian bookworm containers and have
similar improvements.

Related: OS#6057
Change-Id: I49aaf62b5b97775f923453611df3b91354a640a0

debian-bookworm-erlang: new docker container

Related: OS#6057
Change-Id: I797ec0e6700860be8fb59bf6b1fab6fa44e53421

debian-bookworm-obs-latest: new container

Related: OS#6057
Change-Id: Ie30135362e37558010f9894bb80a3684786f5aee