chore(deps): bump watchdog from 2.1.9 to 2.2.1 in /docs/_build

Bumps [watchdog](https://github.com/gorakhargosh/watchdog) from 2.1.9 to 2.2.1.
- [Release notes](https://github.com/gorakhargosh/watchdog/releases)
- [Changelog](https://github.com/gorakhargosh/watchdog/blob/master/changelog.rst)
- [Commits](https://github.com/gorakhargosh/watchdog/compare/v2.1.9...v2.2.1)

---
updated-dependencies:
- dependency-name: watchdog
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

docs/_build/requirements.txt

@@ -19,5 +19,5 @@ PyYAML==6.0
 pyyaml_env_tag==0.1
 six==1.16.0
 soupsieve==2.3.2.post1
-watchdog==2.1.9
+watchdog==2.2.1
 zipp==3.12.1