suspend-manager: Inhibit via gnome-session rather than systemd
* session-manager: Allow to inhibit suspend
* suspend-manager: Inhibit via gnome-session rather than systemd
The systemd inhibitor would ensure we don't suspend when e.g. another
session is active. What we're interested about here is the user's
session though so use gnome-session to prevent suspend instead.
We use a sync DBus call here which should be fine and not block and we
can't do much without gnome-session running anyway.
For the systemd bits see https://github.com/systemd/systemd/issues/29818
Closes: #1001 (closed)