[jdk21u-dev] RFR: 8313612: Use JUnit in lib-test/jdk tests

[Goetz Lindenmaier]

I backport this for parity with 21.0.4-oracle.

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Commit messages:
 - Backport a35e96a3fae8722eea1d266beab22556c784241d

Changes: https://git.openjdk.org/jdk21u-dev/pull/362/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=362&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8313612
  Stats: 301 lines in 5 files changed: 45 ins; 28 del; 228 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/362.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/362/head:pull/362

PR: https://git.openjdk.org/jdk21u-dev/pull/362