RFR: 8126: Update to Eclipse 2023-09

[Marcus Hirt]

...also fixing some checkstyle complaints.

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Commit messages:
 - Fixing copyright year
 - Fixing some checkstyle complaints
 - 8126: Update to Eclipse 2023-09

Changes: https://git.openjdk.org/jmc/pull/525/files
 Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=525&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-8126
  Stats: 41 lines in 8 files changed: 22 ins; 6 del; 13 mod
  Patch: https://git.openjdk.org/jmc/pull/525.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/525/head:pull/525

PR: https://git.openjdk.org/jmc/pull/525