Removes every dependency precompiled installed in the current
_build (this MIX_ENV and MIX_TARGET), so the next mix compile
compiles them from source (or installs them again, when the library is
on). Only build dirs that carry the provenance file an install writes
are removed; a dependency Mix compiled is never touched.
mix precompiled.clean # this build's installs
mix precompiled.clean --cache # also the downloaded files, manifests and scansTrust state (batch sequence, adopted roots) is never removed.