I've tagged and pushed the base image to base:latest (base:20250211.1 has been
built by jenkins).

```
tony@kessel:~/work/inria/repo/swh/sysadm-environment/swh-apps (master) $ docker tag container-registry.softwareheritage.org/swh/infra/swh-apps/base:20250211.1
container-registry.softwareheritage.org/swh/infra/swh-apps/base:latest
tony@kessel:~/work/inria/repo/swh/sysadm-environment/swh-apps (master) $ docker push container-registry.softwareheritage.org/swh/infra/swh-apps/base:latest
The push refers to repository [container-registry.softwareheritage.org/swh/infra/swh-apps/base]
24f1bb282167: Layer already exists
5f70bf18a086: Layer already exists
8b5b3a8db38d: Layer already exists
cc8c3d91a205: Layer already exists
29f95138ec86: Layer already exists
ca3e6f391164: Layer already exists
8f0805620093: Layer already exists
dafb8aed9f7f: Layer already exists
41d4dc7516bb: Layer already exists
c0f51bbdc37d: Layer already exists
91b542912d12: Layer already exists
latest: digest:
sha256:54f4fa022728762166b220adcd6e5d35ef4ef3fb1332e1d2a7ae95c869cee21e size:
2637
```

Refs. sysadm-environment#5560

Refs. sysadm-environment#5560

It's copied at the end of the Dockerfile so modification to it do not rebuild
deps. The entrypoint script is also adapted to work with actual docker run

The environment variable SWH_LOG_LEVEL will be declared in swh-charts.

Refs. sysadm-environment#5321

Related to sysadm-environment#4707

It makes impossible to run apt after, which can make the debugging
complicated if some packages need to be added during a debug session