FD-577: Support Node 24

[NateWaldschmidt]

Summary

Updates the project to ensure support of Node 24 as the primary version and adds testing across Node 20, 22, and 24.

Changes:

• Updated .node-version from 20.19.4 to 24.15.0
• Updated CI workflow to test against Node 20, 22, and 24

Testing

• Run tests locally with Node 24: npm test
• Verify tests pass against all Node versions in CI

Checklist

• Changes tested locally
• CI should pass across all supported Node versions

[gemini-code-assist]

Code Review

This pull request updates the .node-version file to version 24.15.0. Feedback indicates that the corresponding CI configuration updates mentioned in the PR description are missing from the current changes.