bad X11 Forwarding performance

[christian-rauch]

Checklist

• [x] I have searched for similar issues.
• [x] For Python issues, I have tested with the latest development wheel.
• [x] I have checked the release documentation and the latest documentation (for main branch).

Describe the issue

When using X forwarding (ssh -XC user@host), the performance is really bad up to the point where the window manager on the server side notified the user that the window does not respond.

Steps to reproduce the bug

1. `ssh -XC user@host`
2. run an example, e.g. `python3 ./examples/python/t_reconstruction_system/dense_slam_gui.py` or `./build/bin/examples/OnlineSLAMRGBD`

Error message

The input and output is very sliggish. I see glitches in the window and "does not respond" notifications.

Eventually, this may lead to crashes of the application and I also see a termination of the ssh session.

Expected behavior

The window should behave normal, like other X11 forwarded 3D applications in Qt etc.

Open3D, Python and System information

- Operating system: Ubuntu 24.04
- Python version: Python 3.12
- Open3D version: master
- System architecture: x86
- Is this a remote workstation?: yes
- How did you install Open3D?: build from source
- Compiler version (if built from source): gcc 13.3.0-6ubuntu2~24.04

Additional information

The same examples behave normal when directly connected to the PC.