RFR: 8355752: Bump minimum boot jdk to JDK 25

[Mikael Vidstedt]

With the JDK 25 GA out it's time to bump the minimum boot JDK version for mainline/JDK 25.

Testing: tier1-5, GHA

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Commit messages:
 - 8355752: Bump minimum boot jdk to JDK 25

Changes: https://git.openjdk.org/jdk/pull/27638/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27638&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8355752
  Stats: 13 lines in 3 files changed: 0 ins; 0 del; 13 mod
  Patch: https://git.openjdk.org/jdk/pull/27638.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27638/head:pull/27638

PR: https://git.openjdk.org/jdk/pull/27638