ci : update windows-blas job to use multi-target OpenBLAS .dll

[danbev]

This issue is related to #2666 (comment), and I think we should consider updating our CI build to use libopenblas.dll to avoid this issue.

We are currently using:

vcpkg install --triplet=${{ matrix.s2arc }}-windows openblas

Which will not include the dynamic feature of OpenBLAS that can detects CPU capabilities at runtime and selects the fastest computation kernel for the running hardware. We could instead use:

vcpkg install openblas[dynamic-arch]

https://vcpkg.link/ports/openblas#features

Trying this out on windows 11 results in the following error:

> vcpkg.exe install openblas[dynamic-arch]
Computing installation plan...
openblas[dynamic-arch] is only supported on '!windows | mingw', which does not match x64-windows. This usually means that there are known build failures, or runtime problems, when building other platforms. To ignore this and attempt to build openblas anyway, rerun vcpkg with `--allow-unsupported`.

We could try using --allow-unsupported or perhaps it might be safer to download from https://github.com/OpenMathLib/OpenBLAS/releases.