Update Node to v20 from v14 (AWS Support Depreciated)
Update GitHub Action steps to latest versions and update from Node v14 to v20.
AWS currently supports the following Node.js versions:
Node.js v22.x (until April 30, 2027) Node.js v20.x (until April 30, 2026) Node.js v18.x (until September 1, 2025)
@horike37 This PR is ready for review.
Suggestion: Since github action on open source repos are free, why not test it over the 3 currently supported runtimes?
And maybe throw in 14.x + 16.x too while at it, since folk could still be updating their existing functions.)
I understand the argument that we shouldn't be supporting people on these runtimes, but if it's not too hard to add in new features and functionality in a backwards compatible way, then it does make it easier to be sure we're not breaking things for existing users we haven't got around to a runtime update (which they should do).