logs are filled with `warning: constant Gem::ConfigMap is deprecated`

/usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb:10: warning: constant Gem::ConfigMap is deprecated

this looks like discussed here. https://github.com/rubygems/rubygems/issues/3068

I am definitively no ruby expert, and I am not sure which of the workaround to take here.