error TS2374: Duplicate index signature for type 'string'

### [READ] Step 1: Are you in the right place?

Yes

### [REQUIRED] Step 2: Describe your environment

* Operating System version: Github Actions
* Firebase SDK version: 11.8.0
* Firebase Product: firestore
* Node.js version: v18.16.0
* NPM version: 11.8.0

### [REQUIRED] Step 3: Describe the problem

#### Steps to reproduce:

I'm simply trying to run `npm run build` whilst using version 11.8.0 of the firebase-admin node package.

Github Actions fails with the following output:
````
node_modules/@google-cloud/firestore/types/firestore.d.ts(23,1): error TS6200: Definitions of the following identifiers conflict with those in another file: DocumentFieldValue, DocumentData, PartialWithFieldValue, WithFieldValue, UpdateData, Primitive, NestedUpdateFields, ChildUpdateFields, AddPrefixToKeys, UnionToIntersection, Firestore, GeoPoint, Transaction, BulkWriter, BulkWriterError, WriteBatch, SetOptions, WriteResult, DocumentReference, DocumentSnapshot, QueryDocumentSnapshot, OrderByDirection, WhereFilterOp, Query, QuerySnapshot, DocumentChangeType, CollectionReference, CollectionGroup, QueryPartition, AggregateField, AggregateFieldType, AggregateSpecData, AggregateQuery, AggregateQuerySnapshot, FieldValue, FieldPath, Timestamp, BundleBuilder, v1beta1, v1, OK, CANCELLED, UNKNOWN, INVALID_ARGUMENT, DEADLINE_EXCEEDED, NOT_FOUND, ALREADY_EXISTS, PERMISSION_DENIED, RESOURCE_EXHAUSTED, FAILED_PRECONDITION, ABORTED, OUT_OF_RANGE, UNIMPLEMENTED, INTERNAL, UNAVAILABLE, DATA_LOSS, UNAUTHENTICATED, Filter, FirebaseFirestore
node_modules/@google-cloud/firestore/types/firestore.d.ts(302,5): error TS2374: Duplicate index signature for type 'string'.
node_modules/@google-cloud/firestore/types/firestore.d.ts(2085,5): error TS2374: Duplicate index signature for type 'string'.
../../../../node_modules/@google-cloud/firestore/types/firestore.d.ts(23,1): error TS6200: Definitions of the following identifiers conflict with those in another file: DocumentFieldValue, DocumentData, PartialWithFieldValue, WithFieldValue, UpdateData, Primitive, NestedUpdateFields, ChildUpdateFields, AddPrefixToKeys, UnionToIntersection, Firestore, GeoPoint, Transaction, BulkWriter, BulkWriterError, WriteBatch, SetOptions, WriteResult, DocumentReference, DocumentSnapshot, QueryDocumentSnapshot, OrderByDirection, WhereFilterOp, Query, QuerySnapshot, DocumentChangeType, CollectionReference, CollectionGroup, QueryPartition, AggregateField, AggregateFieldType, AggregateSpecData, AggregateQuery, AggregateQuerySnapshot, FieldValue, FieldPath, Timestamp, BundleBuilder, v1beta1, v1, OK, CANCELLED, UNKNOWN, INVALID_ARGUMENT, DEADLINE_EXCEEDED, NOT_FOUND, ALREADY_EXISTS, PERMISSION_DENIED, RESOURCE_EXHAUSTED, FAILED_PRECONDITION, ABORTED, OUT_OF_RANGE, UNIMPLEMENTED, INTERNAL, UNAVAILABLE, DATA_LOSS, UNAUTHENTICATED, Filter, FirebaseFirestore
../../../../node_modules/@google-cloud/firestore/types/firestore.d.ts(302,5): error TS2374: Duplicate index signature for type 'string'.
../../../../node_modules/@google-cloud/firestore/types/firestore.d.ts(2085,5): error TS2374: Duplicate index signature for type 'string'.
npm ERR! Lifecycle script `build` failed with error:
npm ERR! Error: command failed
npm ERR! in workspace: ...
npm ERR! at location: ...
Error: Process completed with exit code 1.
````
#### Relevant Code:

```
package.json:

"dependencies": {
"firebase-admin": "^11.8.0",
"firebase-functions": "^4.4.0",
"pg": "^8.10.0"
},
"devDependencies": {
"@types/pg": "^8.6.6",
"firebase-functions-test": "^3.0.0"
}
```