RFR: 8297067: Update Gradle to 7.6

Fri Dec 16 01:49:14 UTC 2022

On Wed, 14 Dec 2022 08:26:35 GMT, Ambarish Rapte <arapte at openjdk.org> wrote:

> This upgrades gradle to 7.6, It is blocker for upgrading Boot JDK to 19.
> gradle 7.3 does not support JDK 19.
> Tested that, gradle 7.6 works with JDK 17, 18, 19.

Looks good.

@johanvos or @tiainen can one of you be the second reviewer?

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Marked as reviewed by kcr (Lead).

PR: https://git.openjdk.org/jfx/pull/973