GetData-0.12.0 release

[gsmecher]

This release adds support for building Python wheels via CMake and scikit-build-core, enabling cross-platform builds for Windows, Linux, and macOS. Python bindings now require Python 3.9+ and support NumPy 2.x.

Build system improvements:

• CMake modernization for Python wheel generation and improved cross-platform compatibility
• Added CI/CD workflows for automated testing on Ubuntu, macOS, and Windows platforms via GitHub Actions
• Improved MSVC (Visual C++) compatibility for native Windows builds

Python bindings:

• Updated to support NumPy 2.x
• Fixed encoding_support return codes
• Improved Python 3.x compatibility in test suite (exception handling, path separators, regex handling for builds without PCRE support)

Compatibility fixes:

• Fixed 64-bit time_t compatibility on 32-bit architectures
• Fixed Python version detection for Python 3.10+
• Updated Fortran support for modern gfortran (>= 10) with -std=legacy and -fallow-argument-mismatch flags
• Fixed MacOS .dylib generation and post-install path demangling
• Bumped minimum automake version to 1.16

[gsmecher]

This PR stacks on the previous one (#21), and I am expecting them to be merged in sequence and possibly squashed along the way. Please comment here on "release ceremony" (version number, ChangeLog/README updates, et cetera). When/if #21 gets merged, squashed, or rebased, I will graft this PR onto whatever results.

[arahlin]

This looks complete to my eye. Will give @ketiltrout a bit of time to comment in case there's anything to add here.

[gsmecher]

Turns out that Windows lacked some plugin support due to the CI/CD environment. I am preparing another PR to bring Windows up to a minimum baseline (including a Python test script to check automatically), and will rebase this PR on top of it once it's complete.

[gsmecher]

I have added the necessary commits to this PR (before the RELEASE commit). Once the build completes without errors, I think we're clear to merge.

[gsmecher]

Along the way, I found a couple of goofs:

• CMake never invoked the BZIP2 tests on any platform, due to a macro naming inconsistency
• Windows encoding tests failed with UNIX-isms (/dev/null)

These are now fixed. As above - when the CI/CD tests run to completion (this time for sure!) we are OK to merge.

[gsmecher]

And, finally, two more Windows fixes

• Tests now use "bzip2 -d" and "gzip -d" rather than "bunzip" or "gunzip" - the unzip variants are apparently not included on Windows.
• Executables (like gzip or bzip2) need to be quoted before calling gd_system() - there may be spaces in paths ("Program Files")

I am pleased to see all tests pass now. @arahlin, @ketiltrout, my apologies for the avalanche of GitHub e-mails you've been receiving.

If you want the complete summary, it's all captured in my comments on the PR. The current commit stack is logical (and you can either merge it as-is, or squash, as you prefer).

Please merge at your leisure (or let me know if you would like to see any more changes.)