Don't default to syslog logging

[seb128]

Let the preferred/configured logging system to be used instead

[seb128]

The issue was raising in the Ubuntu review for promotion to main
https://bugs.launchpad.net/ubuntu/+source/gamemode/+bug/1853830

However, I don’t understand why the systemd service is called with -l (log to syslog), which is out default for systemd service (the journal forwards to syslog, even for user services). The day we want to remove syslog completely, it will prevent having to patch it.

That's a valid point, forwaring to syslog is configured by the distribution/sysadmin when wanted, there is no reason individual services need to enforce the option

[mdiluz]

Ah, my bad here - I'd not known the defaults would correctly forward the output if it wasn't specified