Bump pytz from 2022.7.1 to 2023.4

Bumps [pytz](https://github.com/stub42/pytz) from 2022.7.1 to 2023.4.
- [Commits](stub42/pytz@release_2022.7.1...release_2023.4)

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

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

requirements.txt

@@ -14,7 +14,7 @@ glyphsLib==6.1.0
 lxml==4.9.1
 openstep-plist==0.3.0
 pyclipper==1.3.0.post3
-pytz==2022.7.1
+pytz==2023.4
 six==1.16.0
 skia-pathops==0.7.2
 ufo2ft==2.33.4