build(deps): 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

@@ -78,7 +78,7 @@ pymemcache==4.0.0
 pyparsing==3.1.1
 python-dateutil==2.8.2
 python-tumblpy==1.1.4
-pytz==2023.3.post1
+pytz==2023.4
 PyYAML==6.0.1
 redis==5.0.1
 requests==2.31.0