bug#59069: `guix shell -CN' failed to access GPU

[Owen T. Heisler]

Hi,

This "works for me" now (tested on Wayland with commit
36bd8e176c1befcc4d959fb1662d8c3e3d0e2474):

```console
$ guix shell -CN mesa-utils --expose=/dev/dri --expose=/sys -E DISPLAY \
       -- glxinfo -B
[does not print errors]
```

Thanks,
Owen