R1:3fbb0309b53f

Update external timezone information to IANA TZDB 2024a

Summary:
Update the list of timezones by pulling from CLDR upstream (revision `9d96f34` from 2024-02-08) located here:

https://github.com/unicode-org/cldr/blob/main/common/supplemental/windowsZones.xml

Permalink:

https://github.com/unicode-org/cldr/blob/9d96f340ab145003b3e6d12d95ffb16f19a8a529/common/supplemental/windowsZones.xml

Closes T15876

Test Plan:
* As an admin, go to http://phorge.localhost/config/edit/phabricator.timezone/ and change…