Gunicorn throws error upon handling SIGINT

**Describe the bug**
When sending a SIGINT to the authentik server gunicorn throws an error.

**To Reproduce**
Steps to reproduce the behavior:

1. Start a shell inside an authentik Docker image
2. Run `dumb-init -- /lifecycle/ak server` and wait for the startup to finish successfully
3. Send a SIGINT to the process i.e. by using the keyboard (CTRL+c)
4. See error

**Expected behavior**
The process should exit without throwing an error.

**Logs**
```
{"event": "Handling signal: int", "level": "info", "logger": "gunicorn.error", "timestamp": 1697581130.2154722}
{"event": "Error while closing socket [Errno 9] Bad file descriptor", "level": "info", "logger": "gunicorn.error", "timestamp": 1697581130.2611558}
{"event": "Error while closing socket [Errno 9] Bad file descriptor", "level": "info", "logger": "gunicorn.error", "timestamp": 1697581130.261223}
{"event": "Worker exiting (pid: 39)", "level": "info", "logger": "gunicorn.error", "timestamp": 1697581130.3631873}
{"event": "Worker exiting (pid: 38)", "level": "info", "logger": "gunicorn.error", "timestamp": 1697581130.3642566}
{"event": "Shutting down: Master", "level": "info", "logger": "gunicorn.error", "timestamp": 1697581130.9277878}
```
**Version and Deployment (please complete the following information):**

- authentik version: 2023.8.3
- Deployment: helm

**Additional context**
This might be related to https://github.com/benoitc/gunicorn/issues/1877 however this issue should have already been fixed in the version that authentik is currently using.