Setup Ruby action deprecation

[teckim]

Description:

I recently set up a new ROR project and added the GitHub actions, and after submitting the PR the rubocop job was failing, the error is in the screenshot below.

Suggested solution:

I investigated the issue, and found out that actions/setup-ruby@v1 should be updated to ruby/setup-ruby@v1 along with ruby-version: '3.0'

If this sounds like a valid issue, I would be happy to open a pull request and discuss the solution.