RFR: 8274274: Update JUnit to version 5.8.1 [v9]

[Johan Vos]

On Mon, 22 Nov 2021 13:43:34 GMT, John Hendrikx <jhendrikx at openjdk.org> wrote:

>> I've added JUnit 5 as a test dependency and made sure that the JUnit 4 tests still work.  Also added a single JUnit 5 tests, and confirmed it works.
>> 
>> I've updated the Eclipse project file for the base module only.
>
> John Hendrikx has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Remove remaining references to old JUnit 4.8.2
>  - Upgrade to JUnit 4.13.2

This looks good. I noticed that the fix for 
8276142: Update gradle to version 7.3
was not in the branch for this PR, but merging it manually  (which will be done when it is merged here) worked and did not cause issues.
I'm running a few more tests, and will approve when they are all green.

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PR: https://git.openjdk.java.net/jfx/pull/633