Remove redundant `!loaded?` condition

Already checked `if !find_target? || loaded?`, unnecessary `!loaded?` in
elsif condition.

activerecord/lib/active_record/associations/collection_association.rb

@@ -227,9 +227,9 @@ def size
           else
             target.size
           end
-        elsif !loaded? && !association_scope.group_values.empty?
+        elsif !association_scope.group_values.empty?
           load_target.size
-        elsif !loaded? && !association_scope.distinct_value && target.is_a?(Array)
+        elsif !association_scope.distinct_value && target.is_a?(Array)
           unsaved_records = target.select(&:new_record?)
           unsaved_records.size + count_records
         else