Remove ruby requirement from Gemfile
We are getting errors from ~"auto devops" as the Ruby version included in the detected buildpack differs slightly.
Given Rails supports Ruby 2.2.2 or later, the chances of incompatible ruby is low, so we don't really need to set Ruby version in Gemfile.
Resolves https://gitlab.com/gitlab-org/gitlab-ce/issues/59205
Edited by 🤖 GitLab Bot 🤖