Concurrent request execution is exponentially slow

**Describe the bug**
Concurrently executing thousands of queries is super slow in dart. For below code it took around ~2s for nodejs version to finish executing and around ~57s for dart version.

**To Reproduce**

The code should call production (actual firestore) APIs and not a local emulator to see the issue.

Dart (Super Slow):
```dart
import 'package:firebase_admin_sdk/firebase_admin_sdk.dart';
import 'package:firebase_functions/firebase_functions.dart';

void main() {
runFunctions((firebase) {
firebase.https.onRequest(name: 'helloWorld', (request) async {
final arr = List.generate(3000, (index) => index);

final firestore = FirebaseApp.instance.firestore();

await Future.wait(
arr.map((index) {
return firestore
.collection('numbers')
.where('number', .equal, index)
.limit(1)
.get();
}),
eagerError: true,
);

return .ok('Yay! Client Exception did not occur.');
});
});
}

```

Typescript (Fast):
```ts
import {initializeApp} from "firebase-admin/app";
import {getFirestore} from "firebase-admin/firestore";
import {onRequest} from "firebase-functions/https";
initializeApp();

export const helloWorld = onRequest(async (_request, response) => {
const arr = Array.from({length: 3000}, (_, index) => index);

const firestore = getFirestore();

await Promise.all(
arr.map((index) => {
return firestore
.collection("numbers")
.where("number", "==", index)
.limit(1)
.get();
}),
);

response.status(200).send("Yay! Client Exception did not occur.");
});

```

**Expected behavior**
The speed of executing thousands of queries concurrently in dart should be as fast as if not faster than nodejs version.