Gem::Source#compact_index_uri

# File tmp/rubies/ruby-4.1.0-preview1/lib/rubygems/source.rb, line 456
def compact_index_uri
  if uri.host == "rubygems.org"
    index_uri = uri.dup
    index_uri.host = "index.rubygems.org"
    index_uri
  else
    uri
  end
end