[jfx20u] RFR: Merge jfx:jfx20

[Kevin Rushforth]

Merge `jfx:jfx20` into `jfx20u:master`

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Commit messages:
 - Merge jfx/jfx20
 - 8304359: Create release notes for JavaFX 20

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

Changes: https://git.openjdk.org/jfx20u/pull/9/files
  Stats: 135 lines in 1 file changed: 135 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jfx20u/pull/9.diff
  Fetch: git fetch https://git.openjdk.org/jfx20u.git pull/9/head:pull/9

PR: https://git.openjdk.org/jfx20u/pull/9