Adding support for macOS to GitHub Actions tests

[AdityyaX]

Increasing Access

Extending GitHub Action tests makes your project more reliable, compatible, and inviting to contributors and users. It ensures smoother functionality across different systems, fosters a welcoming community, and maintains high quality through continuous testing, ultimately increasing access to and adoption of your project.

Most appropriate sub-area of p5.js?

Other (specify if possible)

Feature request details

To extend the workflow to cover Windows as well