Revert "sdk/enter: unconditionally unset GNUGHOME"
Revert "sdk/enter: unconditionally unset GNUGHOME"

This reverts commit 399def45fd01e8e356a536cac57c5b7983ff21c0.

dm0-/mantle,glevand/coreos--mantle,dm0-/mantle,glevand/coreos--mantle