RFR: Merge openjdk/jdk21u-dev:master

[William Kemper]

Merges tag jdk-21.0.3+7

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Commit messages:
 - 8327391: Add SipHash attribution file

The merge commit only contains trivial merges, so no merge-specific webrevs have been generated.

Changes: https://git.openjdk.org/shenandoah-jdk21u/pull/27/files
  Stats: 150 lines in 1 file changed: 150 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/shenandoah-jdk21u/pull/27.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk21u.git pull/27/head:pull/27

PR: https://git.openjdk.org/shenandoah-jdk21u/pull/27