contrib/systemd/qemu-guest-agent.service, tests/data/test-qga-config
and tests/data/test-qga-os-release belong to the guest agent, so make
sure that these files are covered here, too.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Message-ID: <20231107101811.14189-1-thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>