Support running Flatpaks in gVisor

### Description

This might be a bit far-fetched, but it would be amazing if Flatpak could use gVisor to strongly isolate applications.

### Is this feature related to a specific bug?

_No response_

### Do you have a specific solution in mind?

Support all of the features needed by Flatpak applications, including GPU acceleration (for Intel/AMD/Nvidia (with libre drivers)/Qualcomm), multimedia (via a virtual device backed by PipeWire), and Wayland.