This is a workaround for a minor annoyance affecting sage developers who update packages on macOS.

python2 urllib works correctly with ssl but the python3 may not (as discussed in #29418). The correct fix is to update sage_bootstrap to initialize certificates, or to use a higher-level library for downloading. The workaround to use python2 gives us a bit of time... until Apple removes python2 from the OS.

CC: @jhpalmieri

Component: build

Author: Matthias Koeppe

Branch: 1d36a2e

Reviewer: John Palmieri

Issue created by migration from https://trac.sagemath.org/ticket/29890