This allows to build the container that will call the generate-frozen-requirements
script.

That will be usable from ci or other sysadm.

Use:
```
cd swh-apps/scripts
docker build -t build-deps .
cd ../../swh-apps
docker run -v $PWD:/src --user 1000 build-deps $APP
```

It used to be necessary for subvertpy packaging.

This creates a new utility image holding the rsvndump pushed in the gitlab registry.

And then adapts the svn loader image to expose that new dependency tool [1]. That will
allow development to use rsvndump instead of svnrdump.

[1]
```
$ docker build -t swh-loader-svn .
$ docker run -ti --rm --user root --entrypoint rsvndump swh-loader-svn --version
rsvndump 0.6.1
Copyright (C) 2008-present Jonas Gehring <jonas@jgehring.net>
Released under the GNU General Public License.
```

Ref. infra/sysadm-environment#4658

This avoids keeping around a useless shell process, and allows killing
the "init" process to always DTRT

Related to infra/sysadm-environment#4673

Ref. infra/sysadm-environment#4670

Ref. infra/sysadm-environment#4670

This allows better caching of modules with no pyproject.toml

Ref. infra/sysadm-environment#4658

Related to infra/sysadm-environment#4659

Related to infra/sysadm-environment#4659

Related to infra/sysadm-environment#4655

Related to infra/sysadm-environment#4655

Related to infra/sysadm-environment#4655

Related to infra/sysadm-environment#4644

Related to infra/sysadm-environment#4606

Related to infra/sysadm-environment#4605

Related to infra/sysadm-environment#4605

Related to infra/sysadm-environment#4605

Related to infra/sysadm-environment#4605

Mostly to take advantage of the performance improvments

Related to infra/sysadm-environment#4626
Related to infra/sysadm-environment#4625

Related to T4607

Related to T4607

The fossology license indexer requires the fossology-nomossa package.

As a pre-requisite, it was ported from the buster package:
```
root@pergamon:.../repository# reprepro copy bullseye-swh buster-swh fossology-nomossa
Exporting indices...
root@pergamon:.../repository# reprepro ls fossology-nomossa | grep bull
fossology-nomossa | 3.1-1~bpo10~swh+1 | bullseye-swh | amd64
```

Related to T4540

Use swh without any hard-coded path

Related to T4540

Related to T4540

Related to T4540

Related to T4540

Related to T4540

Related to T4391

Related to T4540

Related to T4540

This also fixes a typo in the Dockerfile.

Related to T4540

This sent celery events at the end of the ingestion which is not required. It's no
longer relevant for the current scheduling management. It's an initial typo when
migrating those workers.

Related to T4540

This sent celery events at the end of the ingestion which is not required. It's no
longer relevant for the current scheduling management. It's an initial typo when
migrating those workers.

Related to T4540

This sent celery events at the end of the ingestion which is not required. It's no
longer relevant for the current scheduling management. It's an initial typo when
migrating those workers.

Related to T4540

This sent celery events at the end of the ingestion which is not required. It's no
longer relevant for the current scheduling management. It's an initial typo when
migrating those workers.

Related to T4540

This sent celery events at the end of the ingestion which is not required. It's no
longer relevant for the current scheduling management. It's an initial typo when
migrating those workers.

Related to T4540