[jdk8u-dev] RFR: 8376225: [8u] GHA: Apply work-around for missing JNF for MacOSX builds

[Severin Gehwolf]

As the title goes. For newer MacOS X SDKs which have the JavaNativeFoundations framework removed from the SDK, one needs to "install" it manually. In this case we are taking it from the applejdk in GHA. This should help getting MacOSX builds going on the `macos-15-intel` GHA runners.

The real fix for this is to remove the JNF dependency from the JDK 8u codebase but this effort will take longer and this is an interim measure (noted as such in the comment).

**Testing**
- Tested it on a branch which has [MacOSX 15 intel runner support](https://github.com/openjdk/jdk8u-dev/pull/738) and this patch on top. See here for the GHA run:  https://github.com/jerboaa/jdk8u-dev/actions/runs/21296331427 (MacOSX builds succeed)

Thoughts?

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Commit messages:
 - 8376225: [8u] GHA: Apply work-around for missing JNF for MacOSX builds

Changes: https://git.openjdk.org/jdk8u-dev/pull/748/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=748&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8376225
  Stats: 16 lines in 1 file changed: 16 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/748.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/748/head:pull/748

PR: https://git.openjdk.org/jdk8u-dev/pull/748