status/network: Do not disable on login screen

We currently disable all network items on both the lock- and login
screen. While it makes sense to be very restrictive on the lock screen,
there are some (fringe) use cases for being more permissive on the
login screen (like remote home directories only accessible via VPN).

There's precedence with the power-off/restart actions to be less
restrictive on the login screen, and since we started respecting
the `network-control` polkit action, it's possible to restore the
old behavior if desired.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1874>

js/ui/status/network.js

@@ -1765,7 +1765,6 @@ class Indicator extends PanelMenu.SystemIndicator {
     _sessionUpdated() {
         const sensitive =
             !Main.sessionMode.isLocked &&
-            !Main.sessionMode.isGreeter &&
             this._configPermission && this._configPermission.allowed;
         this.menu.setSensitive(sensitive);
     }