Revert "rely on run_exports, don't use separate iconv on linux"
Revert "rely on run_exports, don't use separate iconv on linux"

This reverts commit 2f5abf9daf6750772d6b6bddd7848fd36b671345.

See discussion in #48 and #49. This change is desirable, but depending
packages need to be migrated to avoid breaking people's setups, and that isn't
expected to happen for a few weeks. So in the name of safety (and getting the
changes of #49 in circulation), back out the change for now.

SymbiFlow/libxml2-feedstock,SymbiFlow/libxml2-feedstock