Bump python-dateutil from 2.8.2 to 2.9.0.post0 in /server

Bumps [python-dateutil](https://github.com/dateutil/dateutil) from 2.8.2 to 2.9.0.post0.
- [Release notes](https://github.com/dateutil/dateutil/releases)
- [Changelog](https://github.com/dateutil/dateutil/blob/master/NEWS)
- [Commits](dateutil/dateutil@2.8.2...2.9.0.post0)

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

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

Author: dependabot[bot]

server/requirements.txt

@@ -1,7 +1,7 @@
 tornado==6.4
 tornado-sqlalchemy==0.7.0
 datetime==4.9
-python-dateutil==2.8.2
+python-dateutil==2.9.0.post0
 pylint-ignore==2022.1025
 marshmallow-sqlalchemy==0.30.0
 tornado-prometheus==0.1.2