cleanup: Use deepUnpack() intead of deep_unpack()

deep_unpack() is just a backwards compability alias for deepUnpack()[1].
The new name makes it more clear that this is not a C function, start to
use it.

[1] 13e662a29d

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2416>

js/misc/loginManager.js

@@ -42,7 +42,7 @@ function canLock() {
                                                Gio.DBusCallFlags.NONE,
                                                -1, null);
 
-        let version = result.deep_unpack()[0].deep_unpack();
+        let version = result.deepUnpack()[0].deepUnpack();
         return haveSystemd() && versionCompare('3.5.91', version);
     } catch (e) {
         return false;