Cygwin CI failing

[roed314]

On every CI run, I'm getting a failure from a misconfigured cygwin CI workflow:

[Invalid workflow file: .github/workflows/ci-cygwin-standard.yml#L1](https://github.com/roed314/sage/actions/runs/4124660481/workflow)
No steps defined in `steps` and no workflow called in `uses` for the following jobs: cygwin-stage-ii-e

I tried fixing the problem in #35005, but gave up since I don't know how to write github workflows. Some possibly relevant discussion: https://stackoverflow.com/questions/73305126/passing-env-variable-inputs-to-a-reusable-workflow and https://github.com/orgs/community/discussions/26671.

It would be nice to fix this, since I'm getting an email about the failed run every time I push to a PR.

[mkoeppe]

This was broken by a failed merge in #32841