refs tails-sysadmin#18194

The gitsquash test calls the corresponding script as a subprocess, which
wants to write logs to /var/log/weblate/update.log. Unfortunately, that
path is not available inside the container images where tests are run.

This commit adds a --testmode option to the script that avoids
configuring the logger, and uses that option when calling the script
during tests.

refs top/tpa/team#42044

ConditionPathExists is actually an option of the [Unit] section.

No need to add WantedBy for the service that is called via the timers,
as we do not want to run the script at boot time.

Thanks, @hefee!

refs tails-sysadmin#18094

refs tails-sysadmin#18094

refs team#42035

refs team#42035

refs tails-sysadmin#18094

The permissions enforcement script expects to be able to create the user
db cache file, so let's allow it to do that by mounting a cache
directory inside the container where the script has permissions to do
its thing.

The config directory (which is the previous location of the user db
cache file) is mounted as read-only inside the container, and the other
directories don't really seem appropriate to host such cache file. Let's
then use a specific bind-mount for that file and make it writable by the
weblate user inside the container.

squash commits

See merge request !17

This file will actually be opened inside the Weblate container, but
we're now trying to open it from a path that only exists outside of the
container.

refs tpo/tpa/tails/sysadmin#18144

WeblatePermission: Handle user renames correctly.

Closes tpo/tpa/tails/sysadmin#18144

See merge request !16