Application Flow Stuck Unless Connection is Explicitly Closed

从提供的 asyncpg 0.30.0 示例开始，在 Python 3.11、PostgreSQL 16 和 Windows 上复现该示例，首先确认使用本地 PostgreSQL 安装时是否会出现此问题。调查 self.get_connection() 周围的异步上下文管理器行为，并将其与显式调用 conn.close() 的情况进行比较；当流程无需显式关闭即可完成时，即视为完成。

• asyncpg version: 0.30.0
• PostgreSQL version: 16
• Do you use a PostgreSQL SaaS? If so, which?: Yes, I am using NeonDB
• Can you reproduce the issue with a local PostgreSQL install?: Didn't attempt it.
• Python version: 3.11.0
• Platform: Windows
• Do you use pgbouncer?: No
• Did you install asyncpg with pip?: Yes
• If you built asyncpg locally, which version of Cython did you use?: [Your Cython version if applicable]
• Can the issue be reproduced under both asyncio and
  uvloop?: [Yes/No] I did not try uvloop

I'm encountering an issue where the flow of my application gets stuck unless the database connection is explicitly closed after a query, even though it should be managed automatically by the context manager.

Code Example:

async def read_record(self, request_details: dict):
    """
    Retrieve records based on conditions and request_type.
    
    Args:
        request_details (dict): The conditions including request_type.
    
    Returns:
        list: The records that match the conditions.
    """
    table = self.get_table_name(request_details['request_type'])
    conditions = {key: request_details[key] for key in request_details if key != 'request_type'}
    condition_str = " AND ".join(f"{key} = ${i+1}" for i, key in enumerate(conditions.keys()))
    query = f"SELECT * FROM {table} WHERE {condition_str};"

    async with self.get_connection() as conn:
        conn.add_log_listener(lambda connection, message: logger.info("PostgreSQL log message: %s", message))
        result = await conn.fetch(query, *conditions.values())
        logger.info("Fetched records: %s", result)
        # await conn.close() # get's stuck without this line

    return result