build: Workaround python3 hash order issues (for now)

build: Workaround python3 hash order issues (for now)

This works around python3 having a new hash seed each time it starts to allow
a second "make" not to rebuild the world.

This should probably be reverted once we find the hash that is causing
the issue, but should reduce frustration for now.

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>