RFR: build: update to JUnit 5.7.1

[Erik Helin]

Hi all,

please review this patch that updates JUnit to version `5.7.1` (and JUnit Platform to `1.7.1`).

Thanks,
Erik

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Depends on: https://git.openjdk.java.net/skara/pull/1086

Commit messages:
 - build: update to JUnit 5.7.1

Changes: https://git.openjdk.java.net/skara/pull/1087/files
 Webrev: https://webrevs.openjdk.java.net/?repo=skara&pr=1087&range=00
  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/skara/pull/1087.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/1087/head:pull/1087

PR: https://git.openjdk.java.net/skara/pull/1087