The change made in #37099 to accommodate the new design of actions/{up,down}load-artifact@v4 broke the upload of macOS wheels to PyPI (see https://github.com/sagemath/sage/actions/runs/9234698750/job/25408786962#step:8:23); this was masked so far because the build of macOS wheels was broken until #36525.

Here we revert to using a separate job that uploads all platform wheels. This uses the new keywords pattern and merge-multiple of actions/download-artifact@v4

Example run: https://github.com/mkoeppe/sage/actions/runs/9291646178/job/25572343853

📝 Checklist

• The title is concise and informative.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation and checked the documentation preview.

⌛ Dependencies