RFR: 7903928: update build.gradle to use JDK 23 [v3]

[Nizar Benalla]

> We've updated native makefile to use JDK 23 (https://github.com/openjdk/jextract/commit/0b89a462146940a2ec90e34eeb5df3d46d8980d2), build.gradle works & expects jdk 23, it still refers to JDK var as "jdk22_home" and passes --release to be 22. Also jextract version is "22".
> 
> The mismatch has caused [some confusion](https://mail.openjdk.org/pipermail/panama-dev/2025-January/020915.html).
> 
> This patch to rename references to `jdk22_home` to `jdk_home`, the jextract version has now been bumped to `23`.
> 
> This PR has been obtained through a `git merge --squash` of #271.
> 
> TIA

Nizar Benalla has updated the pull request incrementally with one additional commit since the last revision:

  nit
  
  Co-authored-by: Chen Liang <liach at openjdk.org>

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

Changes:
  - all: https://git.openjdk.org/jextract/pull/275/files
  - new: https://git.openjdk.org/jextract/pull/275/files/703b3d8a..259c417a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jextract&pr=275&range=02
 - incr: https://webrevs.openjdk.org/?repo=jextract&pr=275&range=01-02

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jextract/pull/275.diff
  Fetch: git fetch https://git.openjdk.org/jextract.git pull/275/head:pull/275

PR: https://git.openjdk.org/jextract/pull/275