[CI] Switch MacOS job from old 12 to new 14

[lukaszstolarczuk]

Change based on the warning in macos 12 job (as brew printed: We (and Apple) do not provide support for this old version.)
// https://github.com/oneapi-src/unified-memory-framework/actions/runs/10994309175/job/30527923269#step:4:10

[ldorau]

The Basic builds / MacOS (macos-14) build failed:

$ python3 -m pip install -r third_party/requirements.txt
error: externally-managed-environment

[lukaszstolarczuk]

The Basic builds / MacOS (macos-14) build failed:

$ python3 -m pip install -r third_party/requirements.txt
error: externally-managed-environment

Done. It seems these reqs are not even used in MacOS workflow - I removed it.

[ldorau]

The Basic builds / MacOS (macos-14) build failed:

$ python3 -m pip install -r third_party/requirements.txt
error: externally-managed-environment

Done. It seems these reqs are not even used in MacOS workflow - I removed it.

Another error now:

Run python3 /Users/runner/work/unified-memory-framework/unified-memory-framework/test/test_installation.py --build-dir /Users/runner/work/unified-memory-framework/unified-memory-framework/build --install-dir /Users/runner/work/unified-memory-framework/unified-memory-framework/../install-dir --build-type Release --disjoint-pool --jemalloc-pool --proxy --umf-version 0.10.0 --shared-library
Traceback (most recent call last):
  File "/Users/runner/work/unified-memory-framework/unified-memory-framework/test/test_installation.py", line [10](https://github.com/oneapi-src/unified-memory-framework/actions/runs/11012391623/job/30579359082?pr=749#step:6:11), in <module>
    from packaging.version import Version
ModuleNotFoundError: No module named 'packaging'
Error: Process completed with exit code 1.

[lukaszstolarczuk]

Another error now:

Run python3 /Users/runner/work/unified-memory-framework/unified-memory-framework/test/test_installation.py --build-dir /Users/runner/work/unified-memory-framework/unified-memory-framework/build --install-dir /Users/runner/work/unified-memory-framework/unified-memory-framework/../install-dir --build-type Release --disjoint-pool --jemalloc-pool --proxy --umf-version 0.10.0 --shared-library
Traceback (most recent call last):
  File "/Users/runner/work/unified-memory-framework/unified-memory-framework/test/test_installation.py", line [10](https://github.com/oneapi-src/unified-memory-framework/actions/runs/11012391623/job/30579359082?pr=749#step:6:11), in <module>
    from packaging.version import Version
ModuleNotFoundError: No module named 'packaging'
Error: Process completed with exit code 1.

I've tested this on my fork, but I guess I done it poorly... Now should be fine...? fingers crossed 😉