build(deps): bump types-python-dateutil from 0.1.4 to 0.1.6

Bumps [types-python-dateutil](https://github.com/python/typeshed) from 0.1.4 to 0.1.6.
- [Release notes](https://github.com/python/typeshed/releases)
- [Commits](https://github.com/python/typeshed/commits)

---
updated-dependencies:
- dependency-name: types-python-dateutil
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements-test.txt

@@ -8,7 +8,7 @@ jsonschema==3.2.0
 coverage==5.5
 doc8==0.9.0
 
-types-python-dateutil==0.1.4
+types-python-dateutil==0.1.6
 types-orjson==0.1.1
 
 pre-commit==2.14.0