Nightly wheels can expire after periods without pushes to `main`

[paumartin2407]

python-flint nightly wheels appear to have disappeared again from the Scientific Python nightly index, which is currently causing SymPy's Bleeding edge dependencies CI job to fail across unrelated PRs.

The current wheel workflow only runs on:

on: [push, pull_request]

and the nightly upload job is restricted to:

if: github.event_name == 'push' && github.ref == 'refs/heads/main'

This means the nightly wheels are only refreshed when something is pushed or merged to main.

This seems related to #418. Since old wheels on the Scientific Python nightly channel are periodically removed, a sufficiently long period without pushes to main can leave downstream projects without any python-flint nightly wheel to install.

For example, SymPy currently fails with:

ERROR: Could not find a version that satisfies the requirement python-flint
ERROR: No matching distribution found for python-flint

in its bleeding-edge dependency job.

Would it make sense to add a scheduled refresh, perhaps weekly, so that the current main state is periodically rebuilt and uploaded even when there has been no repository activity?

I could see two possible approaches:

• schedule the existing wheel workflow periodically, or
• add a smaller dedicated nightly-wheel workflow that only builds/uploads the artifacts needed for the Scientific Python nightly index.

I'd be happy to implement whichever approach and cadence you prefer.

[oscarbenjamin]

We just need to push something every now and again. There were some problems though that I fixed in gh-432 to get CI working again here.