Bump watchdog from 5.0.3 to 6.0.0 in /docs

Bumps [watchdog](https://github.com/gorakhargosh/watchdog) from 5.0.3 to 6.0.0.
- [Release notes](https://github.com/gorakhargosh/watchdog/releases)
- [Changelog](https://github.com/gorakhargosh/watchdog/blob/master/changelog.rst)
- [Commits](gorakhargosh/watchdog@v5.0.3...v6.0.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

docs/requirements.txt

@@ -28,5 +28,5 @@ six==1.16.0
 termcolor==2.5.0
 urllib3==2.2.3
 verspec==0.1.0
-watchdog==5.0.3
+watchdog==6.0.0
 mkdocs-ezglossary-plugin==1.7.1