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

[Athijegannathan Sundararajan]

> We've updated native makefile to use JDK 23 (
> https://github.com/openjdk/jextract/commit/0b89a462146940a2ec90e34eeb5df3d46d8980d2 )
> 
> While 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".

Athijegannathan Sundararajan has updated the pull request incrementally with one additional commit since the last revision:

  fixed jdk23_home in github test.yml.
  
  changed Python sample so that it does not fail with unsupported type
  _Float16

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

Changes:
  - all: https://git.openjdk.org/jextract/pull/271/files
  - new: https://git.openjdk.org/jextract/pull/271/files/d39ed3c7..d44a111c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jextract&pr=271&range=01
 - incr: https://webrevs.openjdk.org/?repo=jextract&pr=271&range=00-01

  Stats: 2 lines in 2 files changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jextract/pull/271.diff
  Fetch: git fetch https://git.openjdk.org/jextract.git pull/271/head:pull/271

PR: https://git.openjdk.org/jextract/pull/271