Bump pytz from 2023.3.post1 to 2023.4

Bumps [pytz](https://github.com/stub42/pytz) from 2023.3.post1 to 2023.4.
- [Commits](stub42/pytz@release_2023.3.post1...release_2023.4)

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

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

requirements.txt

@@ -25,5 +25,5 @@ more-itertools==9.0.0
     # via maus
 packaging==23.0
     # via marshmallow
-pytz==2023.3.post1
+pytz==2023.4
     # via -r requirements.in