[jdk21u-dev] RFR: 8357173: Split jtreg test group jdk tier3

[Goetz Lindenmaier]

I backport this for parity with 21.0.9-oracle.

Trivial resolves because head has jdk_since_checks

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Commit messages:
 - Backport afcbf6b2f49c00a544e6db5b4ed9da76c0bdcba4

Changes: https://git.openjdk.org/jdk21u-dev/pull/2000/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2000&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8357173
  Stats: 12 lines in 1 file changed: 10 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2000.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2000/head:pull/2000

PR: https://git.openjdk.org/jdk21u-dev/pull/2000