This functionality is now handled by core as of the previous commit.
I wanted this to be a standalone commit because the deleted code
makes a reference to remotefilelog's file type missing a node() method
and this may have implications to narrow+remotefilelog usage. The code
in core doesn't perform this check and therefore behavior may be subtly
different and buggy.
But I /think/ the check is merely a performance optimization and
nothing more. So I'm optimistic this will continue to "just work."