DeprecationWarning: The loop argument is deprecated since Python 3.8, and scheduled for removal in Python 3.10.

还没有人认领这个 Issue。

* **asyncpg version**: 0.22.0
* **PostgreSQL version**: local `postgres:13-alpine` via Docker
* **Python version**: 3.9.1
* **Platform**: macOS 11.2.3; Linux 4.19.121 (via Docker Desktop for Mac)
* **Do you use pgbouncer?**: no
* **Did you install asyncpg with pip?**: via poetry

The following warning is produced when running a [simple CRUD example from SQLAlchemy's docs](https://docs.sqlalchemy.org/en/14/orm/examples.html#examples-asyncio):

```
/usr/local/lib/venv/someproject-asdfqwer-py3.9/lib/python3.9/site-packages/asyncpg/connect_utils.py:544: DeprecationWarning: The loop argument is deprecated since Python 3.8, and scheduled for removal in Python 3.10.
tr, pr = await loop.create_connection(
```

从 asyncpg/connect_utils.py 大约第 544 行开始，使用 issue 中链接的 SQLAlchemy asyncio CRUD 示例重现该警告。检查连接的创建方式，并验证该示例在保留连接行为的同时不再发出 Python 3.9 弃用警告。

由索引模型根据 Issue 内容生成。