* bpo-24746: Avoid stripping trailing whitespace in doctest fancy diff

* [2.7] bpo-24746: Avoid stripping trailing whitespace in doctest fancy diff (GH-10639).
(cherry picked from commit cbb16459)
Co-authored-by: Sanyam Khurana <8039608+CuriousLearner@users.noreply.github.com>