Thanks! And revert #3758 here too?

The 3.9 on macos-latest failure is unrelated: GitHub has updated macos-latest from macos-12 to macos-14-arm64 and https://github.com/actions/setup-python now gives:

Error: The version '3.9' with architecture 'arm64' was not found for macOS 14.4.1.
The list of all available versions can be found here: https://raw.githubusercontent.com/actions/python-versions/main/versions-manifest.json

• macos-12 https://github.com/python/peps/actions/runs/8731054516/job/23955857090
• macos-14-arm64 https://github.com/python/peps/actions/runs/8798786342/job/24146487189

The same thing happens for 3.8 and 3.9 in other repos: https://github.com/hugovk/test/actions/runs/8798949098

Let's merge, I'll check what's up on GitHub's side, maybe related to https://github.blog/changelog/2024-04-01-macos-14-sonoma-is-generally-available-and-the-latest-macos-runner-image/.

Someone already reported this in January :)

GitHub are not planning on supporting Python 3.9 and older on Apple Silicon:

• Add Python 3.9 to macos-14 actions/runner-images#9258 (comment)
• Python3.9 on aarch64 for macOS 13.4.1. actions/setup-python#696 (comment)

So we'll need to do something like Backblaze/B2_Command_Line_Tool#1018 and use macos-12 or macos-13 for 3.9.