gh-102158: Add tests for `softkwlist` (GH-102159)


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(cherry picked from commit 9f3ecd1aa3566947648a053bd9716ed67dd9a718)

Co-authored-by: Eclips4 <80244920+Eclips4@users.noreply.github.com>
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
1 file changed