systemd: add GIO_USE_VFS=local environment variable

Avoids GIO to connect to the session bus. This prevents wireplumber to receive
a SIGTERM signal when the dbus service is restarted.
6 jobs for sigterm-fix in 1 minute and 10 seconds (queued for 18 seconds)
Status Name Job ID Coverage
  Container
passed container_fedora #13930369

00:00:14

passed container_ubuntu #13930370

00:00:14

 
  Build
passed build_on_fedora_no_docs #13930372

00:00:46

passed build_on_fedora_with_docs #13930371

00:00:55

passed build_on_ubuntu_no_gir #13930374

00:00:36

passed build_on_ubuntu_with_gir #13930373

00:00:37