fix: ensure external @types aren't picked up in test

some indirect dependencies install @types packages which are not compatible with the older typescript. adjusted test's tsconfig to not pick these up automatically, as the actual .d.ts does not depend on these external types.

types/tsconfig.json

@@ -9,8 +9,9 @@
     "noEmit": true,
 
     "baseUrl": ".",
+    "types": [],
     "paths": {
       "handlebars": ["."]
     }
   }
-}
+}