src/meta-openembedded:python3-watchdog: upgrade 2.1.5 -> 2.1.6

2.1.6
~~~~~
2021-10-01 • `full history <https://github.com/gorakhargosh/watchdog/compare/v2.1.5...v2.1.6>`__

- [bsd] Fixed returned paths in ``kqueue.py`` and restored the overall results of the test suite. (`#842 <https://github.com/gorakhargosh/watchdog/pull/842>`_)
- [bsd] Updated FreeBSD CI support .(`#841 <https://github.com/gorakhargosh/watchdog/pull/841>`_)
- [watchmedo] Removed the ``argh`` dependency in favor of the builtin ``argparse`` module. (`#836 <https://github.com/gorakhargosh/watchdog/pull/836>`_)
- [watchmedo] Removed unexistant ``WindowsApiAsyncObserver`` references and ``--debug-force-winapi-async`` arguments.
- [watchmedo] Improved the help output.
- Thanks to our beloved contributors: @knobix, @AndreaRe9, @BoboTiG

Signed-off-by: Zheng Ruoqin <zhengrq.fnst@fujitsu.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Trevor Gamblin <trevor.gamblin@windriver.com>