Change 'sage_setup: distribution' headers from sage-... to sagemath-... #31031
Description
(and change setup.py accordingly)
to reflect the naming scheme selected in #30912
CC: @dimpase @jhpalmieri @kliem
Component: build
Keywords: sd111
Author: Matthias Koeppe
Branch/Commit: 9dcd479
Reviewer: Travis Scrimshaw
Issue created by migration from https://trac.sagemath.org/ticket/31031