Update watchdog requirement in /requirements

Updates the requirements on [watchdog](https://github.com/gorakhargosh/watchdog) to permit the latest version.
- [Release notes](https://github.com/gorakhargosh/watchdog/releases)
- [Changelog](https://github.com/gorakhargosh/watchdog/blob/master/changelog.rst)
- [Commits](gorakhargosh/watchdog@v2.1.0...v5.0.3)

---
updated-dependencies:
- dependency-name: watchdog
  dependency-type: direct:production
...

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

requirements/requirements.txt

@@ -1,6 +1,6 @@
 requests>=2.26, <3.0
 python-dateutil>=2.6, <3.0
-watchdog>=2.1, <3.0
+watchdog>=2.1, <6.0
 combo-lock>=0.2.2, <0.3
 
 padacioso>=0.2.4,<1.0.0