Fix failing tests on Windows

[mariosasko]

This PR makes necessary changes in the codebase to fix 2 failing tests on Windows (tests/test_spacy_udpipe.py::test_pipe and tests/languages/en/test_en_language.py::test_spacy_udpipe_pretokenized) and improves style.

Changes:

• adds the __reduce__ dunder to UDPipeModel for nlp.pipe support on Windows
• uses Word.setSpaceAfter to set the misc field instead of manually setting it (word.misc = "SpaceAfter=No")
• removes unnecessary "inherit from object" from class declarations

[mariosasko]

Think we should add windows-latest to the list of runners in the workflows file to avoid such errors in the future (the repo is public so adding it should be free).