extensionPrefs: Fake Config module

We include config.js because it is a dependency of ExtensionUtils,
but it's not actually used in the code paths we exercise.

As we want to allow stand-alone builds of the app, it is much easier to
fake the module than to either include a generated file from elsewhere
in the tree or generate it ourselves.

https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1133

js/extensionPrefs/js/meson.build

@@ -22,13 +22,10 @@ configure_file(
   install_dir: pkgdatadir,
 )
 
-config_dir = '@0@/../..'.format(meson.current_build_dir())
-
 gnome.compile_resources(
   app_id + '.src',
   app_id + '.src.gresource.xml',
-  dependencies: [config_js],
-  source_dir: ['.', '../..', config_dir],
+  source_dir: ['.', '../..'],
   gresource_bundle: true,
   install: true,
   install_dir: pkgdatadir

js/extensionPrefs/js/misc/config.js

@@ -0,0 +1 @@
+/* Fake module to satify import in ExtensionUtils */