Select from table through ShardingSphere not working through asyncpg

## Bug Report

**For English only**, other languages will not accept.

Before report a bug, make sure you have:

- Searched open and closed [GitHub issues](https://github.com/apache/shardingsphere/issues).
- Read documentation: [ShardingSphere Doc](https://shardingsphere.apache.org/document/current/en/overview).

Please pay attention on issues you submitted, because we maybe need more details.
If no response anymore and we cannot reproduce it on current information, we will **close it**.

Please answer these questions before submitting your issue. Thanks!

### Which version of ShardingSphere did you use?
ShardingSphere Proxy 5.3.2
### Which project did you use? ShardingSphere-JDBC or ShardingSphere-Proxy?
ShardingSphere- Proxy
### Expected behavior
Select from tables through ShardingSphere should work. When we replace the database connection parameters with a direct postgres database then we are able to do a select on table.
### Actual behavior
Select from tables through ShardingSphere are not working.
The issue is mentioned below:-
`asyncpg.exceptions._base.InternalClientError: cannot switch to state 12; another operation (2) is in progress
`
### Reason analyze (If you can)

### Steps to reproduce the behavior, such as: SQL to execute, sharding rule configuration, when exception occur etc.

### Example codes for reproduce this issue (such as a github link).
```
import asyncio
import asyncpg

async def run():
conn = await asyncpg.connect(user='root', password='root',
database='hint_db', host='127.0.0.1', port=3307)
values = await conn.fetchval(
'SELECT * FROM tracking_info;'
)
print(values)
await conn.close()

loop = asyncio.get_event_loop()
task = loop.create_task(run())
loop.run_until_complete(task)
```

Start with the provided asyncpg reproduction script and the ShardingSphere Proxy 5.3.2 setup, comparing its SELECT behavior with the direct PostgreSQL connection described in the issue. A complete fix should allow the table query to succeed through the proxy without the asyncpg “another operation is in progress” error.

Written by the indexing model from the issue text.