[jfx17u] RFR: 8371015: Change JavaFX release version to 17.0.18 in jfx17u

[Johan Vos]

Bump release version to 17.0.18

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Commit messages:
 - Bump release version to 17.0.18

Changes: https://git.openjdk.org/jfx17u/pull/240/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx17u&pr=240&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8371015
  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jfx17u/pull/240.diff
  Fetch: git fetch https://git.openjdk.org/jfx17u.git pull/240/head:pull/240

PR: https://git.openjdk.org/jfx17u/pull/240