gh-75729: Fix os.spawn tests not handling spaces on Windows (GH-99150)

* Quote paths in os.spawn tests on Windows so they work with spaces

* Add NEWS entry for os spawn test fix

* Fix code style to avoid double negative in os.spawn tests

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

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(cherry picked from commit a34c79623877a7ed0c86a6d48ddccffa0de76836)

Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>