git: openjdk/jfx: master: 8321603: Bump minimum JDK version for JavaFX to JDK 21

[Kevin Rushforth]

Changeset: afa206b5
Author:    Kevin Rushforth <kcr at openjdk.org>
Date:      2024-02-23 15:00:08 +0000
URL:       https://git.openjdk.org/jfx/commit/afa206b546a580a784d830712be174bb84f09ee9

8321603: Bump minimum JDK version for JavaFX to JDK 21

Reviewed-by: angorya, jvos, prr

! CONTRIBUTING.md
! build.gradle
! build.properties