Updates the boot JDK used to build JavaFX 16 to JDK 15. The minimum remains at JDK 11.
Note to reviewers: the build number for JDK 15 GA is the same as JDK 14 GA, so that property is intentionally unchanged (I didn't forget to update it). ------------- Commit messages: - 8253123: Switch FX build to use JDK 15 as boot JDK Changes: https://git.openjdk.java.net/jfx/pull/306/files Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=306&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8253123 Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod Patch: https://git.openjdk.java.net/jfx/pull/306.diff Fetch: git fetch https://git.openjdk.java.net/jfx pull/306/head:pull/306 PR: https://git.openjdk.java.net/jfx/pull/306
