Migrate CI from Volta to Corepack

[chrisgervang]

Volta is now unmaintained, so it's in our interest to move away from it to an official solution.

Benchmark: Currently it takes a minute to install yarn packages (example). This change maintains a minutes (see this run), so I feel confident this doesn't have a negative impact on our build times.

Summary

Migrates the project's automated build system from Volta to Corepack for managing Node.js and Yarn versions in GitHub Actions workflows.

This change modernizes the CI infrastructure while maintaining backward compatibility for local development - developers can continue using Volta, or switch to nvm, fnm, or any other Node version manager.

Changes

• Added .nvmrc file with Node 18.19.0 for compatibility with multiple version managers
• Updated .github/workflows/test.yml - All 3 jobs now use actions/setup-node + Corepack
• Updated .github/workflows/release.yml - Release job now uses Corepack
• Updated .github/workflows/website.yml - Website deployment now uses Corepack with improved caching
• Updated CONTRIBUTING.md - Documentation reflects CI uses Corepack, with local dev flexibility
• Preserved Volta configuration in package.json for developers who prefer it

Technical Details

• Replaced volta-cli/action with actions/setup-node using node-version-file: '.nvmrc'
• Added corepack enable yarn step in all workflows
• Enabled yarn caching via actions/setup-node for faster builds
• Leveraged existing packageManager: "yarn@1.22.19" field for Corepack

Testing

CI will validate this change. The cache behavior will be monitored to ensure proper functionality.

---

Note

Switches CI from Volta to Corepack via actions/setup-node with .nvmrc and yarn caching; adds .nvmrc and updates contributing docs.

• CI/Workflows:
  • Migrate Node setup from volta-cli/action to actions/setup-node across workflows/{test,release,website}.yml using .nvmrc and yarn cache.
  • Enable Corepack (corepack enable yarn) in all workflows.
• Tooling:
  • Add .nvmrc specifying Node 18.19.0.
• Docs:
  • Update CONTRIBUTING.md to note CI uses Corepack and allow local dev with Volta/NVM or other managers.

^{Written by Cursor Bugbot for commit 5c142a9. This will update automatically on new commits. Configure here.}

[chrisgervang]

I've switched to fnm, which is a drop-in replacement for nvm written in rust. I figure most people are using either of these since they are the "official" solutions on https://nodejs.org/en/download

[coveralls]

coverage: 91.055%. remained the same
when pulling 5c142a9 on migrate-to-corepack
into 528bb50 on master.

[chrisgervang]

Rerunning the jobs show the cache hit decreased install times from from 1 minute to 30 seconds.

[chrisgervang]

Of note, the volta action doesn't actually include a yarn cache so this input never did anything

https://github.com/volta-cli/action

[felixpalmer]

Happy to see this 👍 , I gave up on Volta on my local machine some time ago (#9577 (comment) & #9523 for context)