fix dsDanger version

Author: timcadman

.github/workflows/build-env.yml

@@ -13,7 +13,7 @@ on:
       danger_version:
         description: 'dsDangerClient branch/tag'
         required: true
-        default: 'v7.0.0-dev'
+        default: 'v6.3.4-dev'
 
 jobs:
   build: