chore: update fusiondart dep to point to fusiondart#main

Author: sneurlax

scripts/app_config/templates/pubspec.template

@@ -70,7 +70,7 @@ dependencies:
   fusiondart:
     git:
       url: https://github.com/cypherstack/fusiondart.git
-      ref: ad8587ef3f4d2ffac86e352a91040f4a3e0bd07c
+      ref: 540d0bc7dc27a97d45d63f412f26818a7f3b8b51
 
   # Utility plugins
   http: ^0.13.0