Node.js 20 actions are deprecated

[Earlopain]

Hi there,

I'm using this action through https://github.com/rubygems/release-gem. Running this action shows a deprecation warning from github about the use of node 20:

Link goes to https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Here is an example workflow https://github.com/ruby/prism/actions/runs/23169365801

[hsbt]

I update @actions/core for that at #380

I will create v2 tag soon.