I see this has been marked as "test needed", but this patch is a change
to Makefile.pre.in, and it's not clear to me how to unit test it using
the existing Python test framework.

FWIW, I've manually tested it (on Linux) by doing ./configure; make;
sudo make install and verifying the absence of (newly installed) idle,
pydoc, and smtpd.py in /usr/local/bin