Fix typo in dataclasses module (GH-21109) (#21111)

Automerge-Triggered-By: @matrixise
(cherry picked from commit 80526f68411a9406a9067095fbf6a0f88047cac5)

Co-authored-by: Jürgen Gmach <juergen.gmach@googlemail.com>

Co-authored-by: Jürgen Gmach <juergen.gmach@googlemail.com>
1 file changed