RFR: 8343490: Update copyright year for JDK-8341692

[SendaoYan]

Hi all,
The copyright year of some files which has been changed by  [JDK-8341692](https://bugs.openjdk.org/browse/JDK-8341692) wasn't update correctly. This PR update the copyright year of [JDK-8341692](https://bugs.openjdk.org/browse/JDK-8341692). Trivial fix, no risk.

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Commit messages:
 - delete tail whitespace of test/hotspot/jtreg/serviceability/dcmd/gc/HeapDumpCompressedTest.java
 - 8343490: Update copyright year for JDK-8341692

Changes: https://git.openjdk.org/jdk/pull/21891/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21891&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8343490
  Stats: 66 lines in 66 files changed: 2 ins; 0 del; 64 mod
  Patch: https://git.openjdk.org/jdk/pull/21891.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21891/head:pull/21891

PR: https://git.openjdk.org/jdk/pull/21891