chore: ignore external @types in tests

- 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": ["."]
     }
   }
-}
+}