feat: updated method prototype to MongoDBService class.

This commit adds the update method prototype to the MongoDBService class in index.ts. This allows the update method to be used with the correct typings. This is related to issue feathersjs#3485

packages/mongodb/src/index.ts

@@ -41,6 +41,7 @@ export class MongoDBService<
     return this._create(data, params)
   }
 
+  async update(id: NullableAdapterId, data: Data, params?: ServiceParams): Promise<Result>
   async update(id: AdapterId, data: Data, params?: ServiceParams): Promise<Result> {
     return this._update(id, data, {
       ...params,