update to tzdata 2025c (very minor change)

git-svn-id: https://svn.r-project.org/R/trunk@89138 00db46b3-68df-0310-9c12-caf00c1e9a41

Author: ripley

src/extra/tzone/Make.zi

@@ -1,6 +1,6 @@
 ## Makefile to be run on a Unix box with zic
 
-VERSION = 2025b
+VERSION = 2025c
 TZDIR = zoneinfo
 TZTMP = tz
 TARFILE = tzdata$(VERSION).tar.gz