Bug 1775247 - Enable widget.use-theme-accent on Windows. r=cmartin

Just like we do in all other platforms where we use the system accent
color.

Differential Revision: https://phabricator.services.mozilla.com/D149878

modules/libpref/init/StaticPrefList.yaml

@@ -13500,11 +13500,7 @@
 # Whether we should use the default accent color or the theme-provided one.
 - name: widget.use-theme-accent
   type: RelaxedAtomicBool
-#if defined(MOZ_WIDGET_GTK) || defined(XP_MACOSX) || defined(ANDROID)
   value: true
-#else
-  value: false
-#endif
   mirror: always
 
 # Whether we should try to use WebRender to render widgets.