fix unbound variable error with CPU_COUNT on GH Actions

[jaimergp]

Checklist

• [X] Used a personal fork of the feedstock to propose changes
• [ ] Bumped the build number (if the version is unchanged)
• [X] Reset the build number to 0 (if the version changed)
• [x] Re-rendered with the latest conda-smithy (Use the phrase code>@<space/conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• [X] Ensured the license file is being packaged.

https://github.com/conda-forge/conda-forge-ci-setup-feedstock/pull/183 introduced this bug. CPU_COUNT is unset on GH Actions, but we have a check later testing its value, which raises unbound variable due to set -u.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[jaimergp]

@conda-forge-admin, please rerender

[github-actions[bot]]

Hi! This is the friendly automated conda-forge-webservice.

I tried to rerender for you, but it looks like there was nothing to do.

This message was generated by GitHub actions workflow run https://github.com/conda-forge/conda-forge-ci-setup-feedstock/actions/runs/1881456673.

[jaimergp]

@conda-forge/core this is ready for review

[hadim]

Thanks! We also noticed this bug on our private conda forge that uses GH Actions.

[hadim]

I confirm the fix.