Merge #1238 (update pytz to 2022.4)

Author: martey

requirements/production.txt

@@ -16,6 +16,6 @@ pinax-eventlog==5.1.1
 pip==22.2.2
 -e git+https://github.com/pretalx/pretalx@27aafeba79e9f33fc07e148b141773180e938883#egg=pretalx[redis]&subdirectory=src
 psycopg2==2.9.3
-pytz==2022.2.1
+pytz==2022.4
 sentry-sdk==1.9.9
 virtualenv==20.16.5