RFR: 7903943: Release jtreg 7.5.1

[Jaikiran Pai]

On Tue, 4 Feb 2025 09:44:41 GMT, Christian Stein <cstein at openjdk.org> wrote:

> Please review this change preparing the `7.5.1` release of `jtreg`.
> 
> The version number `7.6` will be restored on the main branch after the release; a dedidated `7.5.x` branch was not required, yet.
> 
> This change also updates the `CHANGELOG.md` file with noteworthy items. It also removes the detailed description of the now removed `LIBRARY.properties` support from the `7.5` section.

Overall looks good to me. The `make/build-support/version-numbers` file will need a copyright year update before integrating.

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Marked as reviewed by jpai (Reviewer).

PR Review: https://git.openjdk.org/jtreg/pull/245#pullrequestreview-2592503677