chores(depends): Removed "file:" dependency.

It's just Visual Studio Code which is causing this, I don't really know why to be honest.

Author: tgbhy

plugins/theme-dark/package.json

@@ -51,8 +51,5 @@
   },
   "engines": {
     "node": ">=8.17.0"
-  },
-  "dependencies": {
-    "@blockly/theme-dark": "file:"
   }
 }