RFR: 7903736: Update GitHub actions used in jtreg's workflows

[Christian Stein]

Please review this change to use Oracle's `setup-java` action in `jtreg` workflows. The `oracle-actions/setup-java` action will take care of delegating to up-to-date actions, such as `actions/setup-java`.

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Commit messages:
 - 7903443: Update GitHub actions used in jtreg's workflows

Changes: https://git.openjdk.org/jtreg/pull/197/files
  Webrev: https://webrevs.openjdk.org/?repo=jtreg&pr=197&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903736
  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jtreg/pull/197.diff
  Fetch: git fetch https://git.openjdk.org/jtreg.git pull/197/head:pull/197

PR: https://git.openjdk.org/jtreg/pull/197