Fix typo in dataclasses module (GH-21109) (#21110)

Automerge-Triggered-By: @matrixise (cherry picked from commit 80526f6) Co-authored-by: Jürgen Gmach <juergen.gmach@googlemail.com> Co-authored-by: Jürgen Gmach <juergen.gmach@googlemail.com>

Author: miss-islington

Lib/dataclasses.py

@@ -1094,7 +1094,7 @@ def _asdict_inner(obj, dict_factory):
  # method, because:
  # - it does not recurse in to the namedtuple fields and
  # convert them to dicts (using dict_factory).
- # - I don't actually want to return a dict here. The the main
+ # - I don't actually want to return a dict here. The main
  # use case here is json.dumps, and it handles converting
  # namedtuples to lists. Admittedly we're losing some
  # information here when we produce a json list instead of a