[jdk25u] RFR: 8357141: Update to use jtreg 7.5.2

Wed Oct 1 16:19:45 UTC 2025

Upgrading jtreg to 7.5.2 to match mainline, on our way to jtreg 8. It is a separate commit, so that we can backout jtreg 8 upgrade separately, if we need.

Additional testing:
 - [ ] GHA
 - [ ] Linux AArch64 server fastdebug, `all`

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Commit messages:
 - Backport fe3be498b83e70a9f4739ddad6642c3aa04a97d3

Changes: https://git.openjdk.org/jdk25u/pull/258/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u&pr=258&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8357141
  Stats: 10 lines in 9 files changed: 0 ins; 0 del; 10 mod
  Patch: https://git.openjdk.org/jdk25u/pull/258.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u.git pull/258/head:pull/258

PR: https://git.openjdk.org/jdk25u/pull/258