fix: install ruby via setup-ruby
fix: install ruby via setup-ruby

It currently needs to be an old one to match what is used in CircleCI.
gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish