RFR: 8310582: Update copyright header for files modified in 2023

[Ambarish Rapte]

Updating last modified year in copyright header of the files that were modified during year 2023.

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Commit messages:
 - 8310582: Update copyright header for files modified in 2023

Changes: https://git.openjdk.org/jfx/pull/1176/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1176&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8310582
  Stats: 328 lines in 328 files changed: 0 ins; 0 del; 328 mod
  Patch: https://git.openjdk.org/jfx/pull/1176.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1176/head:pull/1176

PR: https://git.openjdk.org/jfx/pull/1176