Remove unnecessary comment in mixin_argument.py

Remove comment about command line arguments order.

Author: PiousCrossten

colcon_mixin/mixin/mixin_argument.py

@@ -193,7 +193,6 @@ def collect_parsers_by_verb(root, parsers, parent_verbs=()):
             # each mixin by prepending its list values, iterating in reverse
             # makes the resulting list follow the order the mixins were given
             # on the command line while keeping any explicit command line
-            # arguments last (see #40)
             for mixin in reversed(args.mixin or ()):
                 mixin_args = mixins[mixin]
                 logger.debug(