nongnu: Use new multiarch-container module for steam.
* nongnu/packages/steam-client.scm: (<nonguix-container>): Remove record-type.
Use equivalent from multiarch-container module instead with additional fields
ld.so.conf and ld.so.cache.
(glibc-for-fhs, fhs-min-libs, fhs-union, ld.so.conf->ld.so.cache,
package->ld.so.conf, nonguix-container->package, make-container-wrapper,
make-container-manifest, make-container-internal, make-container-script):
Remove. Use equivalents from multiarch-container module instead.
Signed-off-by: ison <ison@airmail.cc>
713f233be7