RFR: 8314484: Update Gradle to 8.4

Thu Oct 12 08:13:22 UTC 2023

On Tue, 10 Oct 2023 17:39:53 GMT, Ambarish Rapte <arapte at openjdk.org> wrote:

> Upgrade gradle to version 8.4.
> It also includes a change for adding task dependency for windows platform that was missed in [JDK-8314486](https://bugs.openjdk.org/browse/JDK-8314486)

tested on Ubuntu 22.04: all good.

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Marked as reviewed by jvos (Reviewer).

PR Review: https://git.openjdk.org/jfx/pull/1257#pullrequestreview-1673561143