Use nixGL to fix nix swayfx on non-NixOS distributions

[WillPower3309]

We need to essentially implement https://pmiddend.github.io/posts/nixgl-on-ubuntu/

[WillPower3309]

We can use the same shell script approach but use the following command to get the processor, then do a string comparison to choose which nixGL binary to use:

❯ cat /proc/cpuinfo | grep vendor_id | head -1 | awk '{print $NF}'
AuthenticAMD