### Description

I want to add support of a separate AWS connection for DynamoDB in `DynamoDBToS3Operator` in `apache-airflow-providers-amazon` via `aws_dynamodb_conn_id` constructor argument.



### Use case/motivation

Sometimes DynamoDB tables and S3 buckets live in different AWS accounts so to access both resources you need to assume a role in another account from one of them.
That role can be specified in AWS connection, thus we need to support two of them in this operator.

### Related issues

_No response_

### Are you willing to submit a PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

hook = DynamoDBHook(aws_conn_id=self.aws_conn_id)
        table = hook.get_conn().Table(self.dynamodb_table_name)
        scan_kwargs = copy(self.dynamodb_scan_kwargs) if self.dynamodb_scan_kwargs else {}
        err = None
        f: IO[Any]
        with NamedTemporaryFile() as f:
            try:
                f = self._scan_dynamodb_and_upload_to_s3(f, scan_kwargs, table)
            except Exception as e:
                err = e
                raise e
            finally:
                if err is None:
                    _upload_file_to_s3(f, self.s3_bucket_name, self.s3_key_prefix, self.aws_conn_id)
    def _scan_dynamodb_and_upload_to_s3(self, temp_file: IO, scan_kwargs: dict, table: Any) -> IO: