RFR: 7903928: update build.gradle to use JDK 23 [v2]

[Athijegannathan Sundararajan]

On Tue, 21 Jan 2025 19:03:52 GMT, Chen Liang <liach at openjdk.org> wrote:

>> README.md line 17:
>> 
>>> 15: ### Building
>>> 16: 
>>> 17: `jextract` depends on the [C libclang API](https://clang.llvm.org/doxygen/group__CINDEX.html). To build the jextract sources, the easiest option is to download LLVM binaries for your platform, which can be found [here](https://releases.llvm.org/download.html) (version 13.0.0 is recommended). Both the `jextract` tool and the bindings it generates depend heavily on the [Foreign Function & Memory API](https://openjdk.java.net/jeps/454), so a suitable [jdk 22+ distribution](https://jdk.java.net/23/) is also required.
>> 
>> This is the only change that wasn't based on review comments, I thought the download page should point to JDK 23
>
> The nominal text should refer to 23, now that gradle passes `--release 23` which is not supported by javac for 22.

Correct. jextract generated code uses JDK 23 specific API => jextract from master build can only be used with JDK 23+

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PR Review Comment: https://git.openjdk.org/jextract/pull/275#discussion_r1924679441