Loosen ruby_parser version dependency

This PR specifies all 3.x versions of ruby_parser greater that 3.1.1

All the metric_fu dependencies the require ruby_parser are on 3.x, but because reek specifies ~> 3.1.1, it prohibits install of any libraries (such as [roodi](https://rubygems.org/gems/roodi)), that require 3.2 or above.