Wrong return type of hGet

### Description

```ts
export const redisClient = createClient(options).withTypeMapping({
  [RESP_TYPES.BLOB_STRING]: String,
});

// Type 'string | {}' is not assignable to type 'string'. Type '{}' is not assignable to type 'string'.ts(2322)
const res: string = await redisClient.hGet("foo", "bar");
```

### Typescript Version

5.8.3

### Node Redis Version

@redis/client 5.5.5
