FindPython: Fix finding NumPy with oneMKL 2026.0

Fix commit 516124ea23 (FindPython: fix regression of NumPy detection
with Intel MKL library, 2024-08-26, v3.30.3~4^2) to apply only on macOS.
It is not needed on other platforms, and oneMKL 2026.0 deprecates SSE4.2.
1 file changed