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/dbusServices/screencast/screencastService.js

@@ -76,7 +76,7 @@ var Recorder = class {
 
     _applyOptions(options) {
         for (const option in options)
-            options[option] = options[option].deep_unpack();
+            options[option] = options[option].deepUnpack();
 
         if (options['pipeline'] !== undefined)
             this._pipelineString = options['pipeline'];