CancelledError exception in shielded future causing Gunicorn worker to exit

### Describe the bug

The Authentik server container is continuously throwing a `CancelledError exception in shielded future` within the Django middleware stack (wrapped by `asgiref/sync.py`). Immediately following these exceptions, Gunicorn throws an `[Errno 9] Bad file descriptor` error, causing the worker to exit and reboot. There is also a timezone warning regarding `CacheEntry.expires` receiving a naive datetime.

### How to reproduce

1. See error in the server logs.

### Expected behavior

The server should handle asynchronous tasks gracefully without dropping connections, and Gunicorn workers should remain stable without restarting.

### Screenshots

_No response_

### Additional context

Deployed a PostgreSQL Cluster

### Deployment Method

Docker

### Version

2026.5.3

### Relevant log output

```shell
{"event": "CancelledError exception in shielded future\nfuture: ", "exception": [...], "frames": [{"filename": "/usr/local/lib/python3.14/concurrent/futures/thread.py", "lineno": 86, "name": "run"}, ..., {"filename": "/authentik/root/middleware.py", "lineno": 331, "name": "__call__"}, ..., {"filename": "/ak-root/.venv/lib/python3.14/site-packages/asgiref/sync.py", "lineno": 523, "name": "__call__"}], "level": "error", "logger": "asyncio", "timestamp": "2026-06-19T09:15:08.050540"}

{"event": "CancelledError exception in shielded future\nfuture: ", "exception": [...], "level": "error", "logger": "asyncio", "timestamp": "2026-06-19T09:15:12.832582"}

{"event": "Error while closing socket [Errno 9] Bad file descriptor", "level": "info", "logger": "gunicorn.error", "timestamp": "2026-06-19T09:15:12.901919"}
{"event": "Worker exiting (pid: 135942)", "level": "info", "logger": "gunicorn.error", "timestamp": "2026-06-19T09:15:13.003582"}
{"event": "Booting worker with pid: 149643", "level": "info", "logger": "gunicorn.error", "timestamp": "2026-06-19T09:15:14.575071"}

/ak-root/.venv/lib/python3.14/site-packages/django/db/models/fields/__init__.py:1671: RuntimeWarning: DateTimeField CacheEntry.expires received a naive datetime (9999-12-31 23:59:59) while time zone support is active.
```

Start with authentik/root/middleware.py around line 331 and trace the asynchronous call through asgiref/sync.py, correlating the cancellation with Gunicorn's socket-close and worker-exit logs. Check the CacheEntry.expires timezone warning separately. Done means the reported cancellation no longer causes worker restarts or dropped connections, with the warning's status explicitly verified.

Written by the indexing model from the issue text.