cleanup: Remove spaces in object literals

We only adopted this style relatively recently, so there's a bit
more to adjust. Still, it's manageable and another step towards
getting rid of the legacy style.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2866>

lint/eslintrc-legacy.yml

@@ -18,6 +18,3 @@ rules:
   jsdoc/require-param-description: off
   jsdoc/require-param-name: off
   jsdoc/require-param-type: off
-  object-curly-spacing:
-    - error
-    - always