scheduler task-type register cli: Some packages do not register any longer

For example, for the svn loader is no longer seen [1]

swh@swh-toolbox-55f7fcf794-m7rwf:~$ swh scheduler -C $SWH_CONFIG_FILENAME task-type register 2>&1 | grep svn

It might be an issue in the loader.svn package but that seems dubious. Before, even when doing nothing, that package was loaded and some report were generated about it in the log output message [3]

Version:

swh@swh-toolbox-55f7fcf794-m7rwf:~$ pip list | grep swh.scheduler
swh.scheduler             2.2.0

[3]

...
INFO:swh.scheduler.cli.task_type:Loading entrypoint for plugin loader.rpm
INFO:swh.scheduler.cli.task_type:Loading entrypoint for plugin loader.rubygems
INFO:swh.scheduler.cli.task_type:Loading entrypoint for plugin swh.vault
...