misc/zoneinfo: update to 2026b
Release 2026b - 2026-04-22 23:06:43 -0700
Changes: https://github.com/eggert/tz/blob/2026b/NEWS
Briefly:
British Columbia moved to permanent -07 on 2026-03-09.
Approved by: skreuzer (maintainer)
MFH: 2026Q2
(cherry picked from commit 5faca35f7b2f1c3503aeeccb6d54dbdd82df6479)