RFR: 8296284: Update CONTRIBUTING guidelines to state that JUnit 5 is used for tests

[Marius Hanl]

On Mon, 16 Jun 2025 15:38:56 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

>> (if possible) ?
>
> minor: maybe move L232 before L231?

> Should we mention about JUnit5 under **Test your changes** ([here](https://github.com/openjdk/jfx/blob/fd30c94893156644c0d803b3e7fd8c9731d65fe6/CONTRIBUTING.md?plain=1#L66)), where we mention that a fix should have associated tests?

I like that idea as well!

-------------

PR Review Comment: https://git.openjdk.org/jfx/pull/1828#discussion_r2150378738