Make JAR dep paths modifiable

[mattjala]

The build system for the java libraries currently forces dependency JARs (e.g. SLF4j) to always be pulled from their bundled location in java/lib.

This PR changes several JAR path variables to CACHE variables, so that users interested in providing their own path to different JARs can do so via -D overrides. Specifically, the altered variables are

• HDF5_JAVA_LOGGING_JAR
• HDF5_JAVA_LOGGING_NOP_JAR
• HDF5_JAVA_LOGGING_SIMPLE_JAR

This PR also moves the JUnit and Hamcrest JAR paths to similarly modifiable cache variables (HDF5_JAVA_JUNIT_JAR and HDF5_JAVA_HAMCREST_JAR) instead of building them inline in a couple different places.

[Copilot]

Pull request overview

This PR makes Java dependency JAR locations configurable via CMake cache variables so consumers can override bundled JAR paths with -D...=... at configure time.

Changes:

• Convert SLF4J dependency JAR path variables to CACHE FILEPATH entries (HDF5_JAVA_LOGGING_JAR, HDF5_JAVA_LOGGING_NOP_JAR, HDF5_JAVA_LOGGING_SIMPLE_JAR).
• Introduce cache variables for JUnit and Hamcrest JAR paths (HDF5_JAVA_JUNIT_JAR, HDF5_JAVA_HAMCREST_JAR) and use them in Java test classpaths.
• Update Java test CMake logic to consume the new cache variables instead of hard-coded ${HDF5_JAVA_LIB_DIR}/... paths.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
CMakeLists.txt	Defines JAR paths as cache variables to allow -D overrides, adds JUnit/Hamcrest cache vars.
java/test/CMakeLists.txt	Uses new JUnit/Hamcrest cache vars in CMAKE_JAVA_INCLUDE_PATH.
java/src-jni/test/CMakeLists.txt	Uses new JUnit/Hamcrest cache vars in CMAKE_JAVA_INCLUDE_PATH.
java/jtest/CMakeLists.txt	Uses new JUnit/Hamcrest cache vars in CMAKE_JAVA_INCLUDE_PATH (both FFM and non-FFM classpaths).

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[jhendersonHDF]

Two other comments:

• A change like this should probably have a CHANGELOG entry
• Copilot has a point in that CMakeInstallation.cmake is hard-coding these JAR names, which can result in the wrong paths being put/used in hdf5-config.cmake. See https://github.com/HDFGroup/hdf5/blob/develop/CMakeInstallation.cmake#L107-L118 and https://github.com/HDFGroup/hdf5/blob/develop/config/install/hdf5-config.cmake.in#L108-L125. There may be other cases being missed; we should quickly test (just manually) with alternative JAR paths to see what the resulting installation looks like and whether it works.

[mattjala]

The most recent changes propagate the user-specified path changes down to hdf5-config.cmake. I also added the CHANGELOG, and tested a local build using a custom path to dependency JARs, which passed the java ctests.

[hyoklee]

Proof: https://github.com/hyoklee/actions/actions/runs/23868895539/workflow

[jhendersonHDF]

Just needs conflict resolving