Add rubygems 3.2.31, remove rubygems 3.2.30
Add rubygems 3.2.31, remove rubygems 3.2.30

for stack(s) cflinuxfs3 [#180235516]

cloudfoundry/ruby-buildpack,cloudfoundry/ruby-buildpack,cloudfoundry/ruby-buildpack,cloudfoundry/ruby-buildpack,cloudfoundry/ruby-buildpack