VNC connection disconnects when idle

### Describe the bug

When connecting to a device via VNC, the connection remains active until the user becomes inactive. After roughly 30 seconds of inactivity, the connection drops until the user reinitiates it through the Authentik dashboard.

If any additional information is needed, please let me know.

There is no reverse proxy in this setup. It is between 3 different devices:
- The Authentik Server
- The Outpost Server
- A Linux Mint Desktop running x11vnc

The RAC Outpost's Configuration in Authentik:
```
log_level: debug
docker_labels: null
authentik_host: https://[]:9443
docker_network: null
container_image: null
docker_map_ports: true
refresh_interval: minutes=5
authentik_host_browser: ""
object_naming_template: ak-%(name)s
authentik_host_insecure: true
```

### How to reproduce

1. Set up the RAC provider as per the documentation
2. Connect to the remote device using the RAC provider.
3. Leave the VNC window idle (no mouse movement, keyboard strokes, etc) for 30~ seconds.
4. The VNC session will say disconnect and will not reconnect.

### Expected behavior

The connection should not drop unless the user disconnects from the VNC session or hits the connection_expiry set in the RAC provider.

### Screenshots

_No response_

### Additional context

_No response_

### Deployment Method

Docker

### Version

2026.5.6

### Relevant log output

```shell
{"event":"guacd[5328]: INFO:\tUser \"@\" joined connection \"$\" (1 users now present)","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:26Z"}
{"event":"guacd[5328]: DEBUG:\tClient has not defined its protocol version.","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:26Z"}
{"event":"guacd[5328]: INFO:\tLocal system reports 4 processor(s) are available.","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:26Z"}
{"event":"guacd[5328]: INFO:\tGraphical updates will be encoded using 4 worker thread(s).","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:26Z"}
{"event":"guacd[5328]: DEBUG:\tScreen data has not been initialized, yet.","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:26Z"}
{"connection":"asgi.specific.","error":null,"event":"removing connection","level":"info","timestamp":"2026-08-26T19:35:51Z"}
{"event":"guacd[5328]: INFO:\tUser \"@\" disconnected (0 users remain)","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:51Z"}
{"event":"guacd[5328]: INFO:\tLast user of connection \"$\" disconnected","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:51Z"}
{"event":"guacd[5328]: DEBUG:\tRequesting termination of client...","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:51Z"}
{"event":"guacd[5328]: INFO:\tInternal VNC client disconnected","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:52Z"}
{"event":"guacd[5328]: DEBUG:\tClient terminated successfully.","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:52Z"}
{"event":"guacd[17]: INFO:\tConnection \"$\" removed.","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:52Z"}
{"event":"guacd[17]: DEBUG:\tUnable to request termination of client process: No such process","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:52Z"}
{"event":"guacd[17]: DEBUG:\tAll child processes for connection \"$\" have been terminated","level":"info","logger":"authentik.outpost.rac.guacd","timestamp":"2026-08-26T19:35:52Z"}
```