contrib/tzdata: import tzdata 2023c

Changes: https://github.com/eggert/tz/blob/2023c/NEWS

The tzdata 2023c release reverts all changes made in 2023b other than
commentary, as that appears to be the best of a bad set of short-notice
choices for modeling this week's daylight saving chaos in Lebanon.

(cherry picked from commit 9fbeeb6e38310b4f42a14c4b043bbee82c5e4752)

Cumulative commit including the following cherry-picks:
9845906f02fea5a4f573a97a85d376acadef8769
f0cea48cb780522234370e122fdb837388b97a06
7da23e6521d171845311817bac904f252a3b4478

Approved by: so
Security: FreeBSD-EN-23:05.tzdata