[jdk21u] RFR: 8352097: (tz) zone.tab update missed in 2025a backport

[Andrew John Hughes]

The [21u backport](https://git.openjdk.org/jdk21u-dev/commit/5d21a2bcc4ba06331df52470795134d8540dd567) of the tzdata 2025a update missed an update to `zone.tab`, as this was not present in the [25u commit]( https://git.openjdk.org/jdk/commit/caa3c78f7837b1f561740184bd8f9cb671c467eb) on which it was based, due to its removal in [JDK-8166983](https://bugs.openjdk.org/browse/JDK-8166983). The change was in [the 24u commit](https://git.openjdk.org/jdk24u/commit/81252ef76899ad95197550a11c2786ccf3cf0cd2) which was applied later than the 21u one.

We should add this missing change to the existing 2025a update in 21.0.7 and consider backporting JDK-8166983 for 21.0.8.

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Commit messages:
 - 8352097: (tz) zone.tab update missed in 2025a backport

Changes: https://git.openjdk.org/jdk21u/pull/460/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=460&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8352097
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk21u/pull/460.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/460/head:pull/460

PR: https://git.openjdk.org/jdk21u/pull/460