RFR: 8339238: Update to use jtreg 7.5.1

[Christian Stein]

Please review the change to update to using jtreg 7.5.1.

The primary change is to the `jib-profiles.js` file, which specifies the version of jtreg to use, for those systems that rely on this file. In addition, the `requiredVersion` has been updated in the various `TEST.ROOT` files.

_Testing..._ tier 1 — tier 8

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Commit messages:
 - Use tagged jtreg version
 - Prepare to use jtreg 7.5.1

Changes: https://git.openjdk.org/jdk/pull/20766/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20766&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8339238
  Stats: 12 lines in 8 files changed: 0 ins; 0 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/20766.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20766/head:pull/20766

PR: https://git.openjdk.org/jdk/pull/20766