RFR: JDK-8321984: IGV: Upgrade to Netbeans Platform 20 [v6]

[Christian Hagedorn]

On Mon, 22 Jan 2024 11:34:38 GMT, Tobias Holenstein <tholenstein at openjdk.org> wrote:

>> Upgraded IGV and dependencies to the newest Netbeans Platform 20 which was released on December 2023.
>> 
>> Tested that IGV still behaves as expected after the upgrade.
>
> Tobias Holenstein has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Revert "make IGV build work with mainline JDK version"
>   
>   This reverts commit 35080de727135741fee96834470072f002c32501.

Looks good!

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Marked as reviewed by chagedorn (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17106#pullrequestreview-1836264005