Update watchdog to 2.1.9

[pyup-bot]

This PR updates watchdog from 2.1.8 to 2.1.9.

Changelog

2.1.9

~~~~~

2022-06-10 • `full history <https://github.com/gorakhargosh/watchdog/compare/v2.1.8...v2.1.9>`__

- [fsevents] Fix flakey test to assert that there are no errors when stopping the emitter.
- [inotify] Suppress occasional ``OSError: [Errno 9] Bad file descriptor`` at shutdown. (`805 <https://github.com/gorakhargosh/watchdog/issues/805>`__)
- [watchmedo] Make ``auto-restart`` restart the sub-process if it terminates. (`896 <https://github.com/gorakhargosh/watchdog/pull/896>`__)
- [watchmedo] Avoid zombie sub-processes when running ``shell-command`` without ``--wait``. (`405 <https://github.com/gorakhargosh/watchdog/issues/405>`__)
- Thanks to our beloved contributors: samschott, taleinat, altendky, BoboTiG

Links

• PyPI: https://pypi.org/project/watchdog
• Changelog: https://pyup.io/changelogs/watchdog/
• Repo: https://github.com/gorakhargosh/watchdog
• Docs: https://pythonhosted.org/watchdog/