Updated tzdb from 2025a to  2025b

2025b announced updates that modify timezones in Chile.

https://lists.iana.org/hyperkitty/list/tz-announce@iana.org/thread/6JVHNHLB6I2WAYTQ75L6KEPEQHFXAJK3/

Manually verified that console.log(new Date().toLocaleString("en-US", {
timeZone: "America/Coyhaique" })); now exists. Previously the timezone
`America/Coyhaique` did not exist and was shared with
`America/Santiago`.

Change-Id: Ibedd5f89bab0031abedff6d49e24535f0199a97e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/deps/icu/+/6478631
Reviewed-by: Shu-yu Guo <syg@chromium.org>