Update javascript engine information

[isacaya]

Updated the changed javascript engine information. (Nashorn -> Graal.js)

[psiinon]

Checkmarx One – Scan Summary & Details – 6518e83e-0285-4061-8135-7e0e5c61bea7

Great job, no security vulnerabilities found in this Pull Request

[psiinon]

Thanks!
FYI the Script Console add-on help also needs to be changed otherwise the corresponding change will be overwritten when it is next released: https://github.com/zaproxy/zap-extensions/blob/main/addOns/scripts/src/main/javahelp/org/zaproxy/zap/extension/scripts/resources/help/contents/scripts.html#L13
However I think its worth update the website directly in this case anyway.

[thc202]

Graal.js is not included by default in all distributions.