chore(client): fix several type errors (#58500)

client/utils/declarations.d.ts

@@ -3,6 +3,7 @@ declare global {
     // This is a feature Gatsby adds to the `window` object.
     // https://github.com/gatsbyjs/gatsby/blob/deb41cdfefbefe0c170b5dd7c10a19ba2b338f6e/packages/gatsby/cache-dir/production-app.js#L28
     ___loader: {
+      enqueue: () => void;
       hovering: (path: string | null) => void;
     };
   }