Merge pull request rails#51652 from heka1024/remove-false-comment

Author: vipulnsward

activesupport/lib/active_support/duration/iso8601_serializer.rb

@@ -35,7 +35,6 @@ def serialize
         # Return pair of duration's parts and whole duration sign.
         # Parts are summarized (as they can become repetitive due to addition, etc).
         # Zero parts are removed as not significant.
-        # If all parts are negative it will negate all of them and return minus as a sign.
         def normalize
           parts = @duration.parts.each_with_object(Hash.new(0)) do |(k, v), p|
             p[k] += v  unless v.zero?