In my previous commit (593c28b) I used the wrong upstream artifact for
the runtime. After reading the documentation in the
ValveSoftware/steam-runtime repo, I now know that the steam-runtime
tarball is what I actually wanted.
I also used 'diff' to compare the various artifacts with the old runtime
this package used before, and the steam-runtime one is certainly the
closest.
Most importantly, switching to the right steam-runtime package
reportedly fixes issues for other users (fixes#90229).
This also entirely removes the amd64/i386 split from runtime.nix because
the upstream package bundles both together, and if that's how upstream
wants to distribute this, it seems best to follow their lead.
Valve has started releasing tarballs of the steam runtime. It seems a
lot easier to download and extract a single tarball than to download a
buncha debs, extract them, and splat em around a bit.
Let's just use the runtime they build. It's a buncha random binary
packages anyway.
Also, the download url for their debs broke, so there's that too.
