Add PyHC Actions for PHEP 3 compliance and environment compatibility

[sapols]

Hey guys, Shawn from PyHC here!

Can I politely ask you to be guinea pigs for these two new GitHub Actions I developed? 😁 I'm asking all the core packages first. The actions check for (1) compliance with PHEP 3 and (2) compatibility with the PyHC Environment. The idea is that they'll pass ✅ if there are no problems, but error/warn when problems arise.

E.g., you'll get a red ❌ if:

• A change to your package would introduce a dependency conflict in the PyHC Environment
• You do not adopt a new Python version or core Scientific Python package version within 6 months of release

You'll get ignorable warnings ⚠️ if:

• You support older Python versions or core Scientific Python packages beyond the required SPEC 0 support window
• You put an upper-bound constraint on a core Scientific Python package
• An optional dependency inside an [extra] would introduce a dependency conflict in the PyHC Environment

If this goes well, I'd love to live in a future where all PyHC packages use these actions. I think it'd help keep everyone on the same page and be a huge win for interoperability!

Summary

This PR adds two GitHub Actions workflows from heliophysicsPy/pyhc-actions:

1. PHEP 3 Compliance Checker

Validates that the package meets PHEP 3 requirements:

• Python version support (36-month support window)
• Core Scientific Python package version support (24-month support window)
• New version adoption within 6 months of release
• Warnings on upper-bound constraints and exact version pins (core Scientific Python packages only)

2. PyHC Environment Compatibility Checker

Detects dependency conflicts with the PyHC Environment to ensure the package can be installed alongside other PyHC packages:

• Errors when conflicts are detected in base package
• Warns when conflicts are detected in optional dependency extras

Trigger Schedule

Both workflows run on:

• Push/PR to master branch
• Quarterly schedule (Jan 1, Apr 1, Jul 1, Oct 1 at 3pm UTC)
• Manual trigger via workflow_dispatch

Notes

• I tested these actions on a personal fork of HAPI Client and pyhc-core, and that went well, so now I'm rolling them out to all core PyHC packages as the first real-world tests.
• The checks should only take a few seconds each to run, largely thanks to uv doing most the heavy lifting.

Feedback

Please share any feedback about how I've implemented these! I've tested them as extensively as I can, but let me know if you experience buggy behavior. I want these to be helpful, not cumbersome.

[sapols]

❌❌ Both the checks failed because it couldn't find a pyproject.toml, which is annoying because there should be fallbacks for that (I'll investigate):

Error: File not found: pyproject.toml
Error: Process completed with exit code 1.

[sapols]

✅✅ Update: Fixed in v1.0.2 of the actions! 🎉