Cleanup unused and not working packages installations (socat)

See merge request nexedi/slapos.package!175

Fix random error "No space left on device".
For documentation, see
https://openbuildservice.org/help/manuals/obs-user-guide/cha.obs.build_job_constraints.html
For a case on OBS forum, see
https://forums.opensuse.org/t/obs-build-build-vm-line-427-echo-write-error-no-space-left-on-device/140717

Support MCA and fluent-bit plugin in separate packages.
Update command-line calls to the programs and files.

Update according to the .cfg file names in slapos repository.

Also update mca--static files:
- Update installation so that it does not install the plugin's files
anymore.
- Update dependencies.

ZC_BUILDOUT_VERSION variable cannot be defined in custom environments.

fluent-bit:
- Fix version number.
- Use home:oph.nxd OBS project.
mca--static:
- Update version.
- Use master branch in slapos repository.
- Use home:oph.nxd OBS project.

See 9bdb1695

by default, the bootstrap script will install newest buildout, but
starting with buildout 3.0.0, there is a problem of wheel like this:

ez_setup.py is deprecated and when using it setuptools will be pinned to 33.1.1 since it's the last version that supports setuptools self upgrade/installation, check https://github.com/pypa/setuptools/issues/581 for more info; use pip to install setuptools
Downloading https://pypi.io/packages/source/s/setuptools/setuptools-41.6.0.zip
Extracting in /tmp/tmpyglw2hza
Now working in /tmp/tmpyglw2hza/setuptools-41.6.0
Building a Setuptools egg in /root/slapos.package/obs/slapos/sn_1.8.3+1.0.290+1/slapos/build/opt/slapos/eggs
warning: no files found matching '*.py' under directory 'tests'
warning: no previously-included files found matching 'pyproject.toml'
/root/slapos.package/obs/slapos/sn_1.8.3+1.0.290+1/slapos/build/opt/slapos/eggs/setuptools-41.6.0-py3.9.egg
Traceback (most recent call last):
  File "/root/slapos.package/obs/slapos/sn_1.8.3+1.0.290+1/slapos/build/opt/slapos/bootstrap.py", line 199, in <module>
    ws.require(requirement)
  File "/root/slapos.package/obs/slapos/sn_1.8.3+1.0.290+1/slapos/build/opt/slapos/eggs/setuptools-41.6.0-py3.9.egg/pkg_resources/__init__.py", line 900, in require
  File "/root/slapos.package/obs/slapos/sn_1.8.3+1.0.290+1/slapos/build/opt/slapos/eggs/setuptools-41.6.0-py3.9.egg/pkg_resources/__init__.py", line 786, in resolve
pkg_resources.DistributionNotFound: The 'wheel' distribution was not found and is required by zc.buildout
Impossible to build SlapOS, exiting.
make: *** [Makefile:9: download_cache] Error 1

The installation is now using cloud-init config instead of preseed files
(see https://ubuntu.com/server/docs/install/autoinstall).

For now, it's not possible to have different file names than "user-data"
and "meta-data" and the hostname is hardcoded in "user-data" so it won't
work for Ubuntu 24.04 (see
https://cloudinit.readthedocs.io/en/latest/topics/datasources/nocloud.html).

So keep everything in the same file

For info, this is the command used:

for f in *.json; do packer fix -validate $f > $f.fix || echo "$f FAILED" ; mv $f.fix $f ; done

TODO: we should make sure the logs are properly uploaded before exiting

fixup of b68b3f17

The VM will use the DNS server coming from qemu-kvm (see
https://wiki.qemu.org/Documentation/Networking#User_Networking_.28SLIRP.29)
so it will actually use the DNS from the host machine.

fixup of b68b3f17

fixup of 0619932c (keep using insecure
http repository for debian 8, 9 and 10)