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/weather.js

@@ -294,7 +294,7 @@ var WeatherClient = class extends Signals.EventEmitter {
     }
 
     _onLocationsChanged() {
-        let locations = this._settings.get_value('locations').deep_unpack();
+        let locations = this._settings.get_value('locations').deepUnpack();
         let serialized = locations.shift();
         let mostRecentLocation = null;