### 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)

while True:
            response = table.scan(**scan_kwargs)
            items = response["Items"]
            for item in items:
                temp_file.write(self.process_func(item))
            if "LastEvaluatedKey" not in response:
                
                break
            last_evaluated_key = response["LastEvaluatedKey"]
            scan_kwargs["ExclusiveStartKey"] = last_evaluated_key
            
            if getsize(temp_file.name) >= self.file_size:
                _upload_file_to_s3(temp_file, self.s3_bucket_name, self.s3_key_prefix, self.aws_conn_id)
                temp_file.close()
                temp_file = NamedTemporaryFile()
        return temp_file