Fix MSYS2 GitHub action

[pedrolcl]

Description

Avoid overriding TEMP environment variable; transform msys2 TEMP using cygpath.

Related Issues

Closes #18

Checklist

• I have followed the contribution guidelines.
• My code follows the coding standards.
• I have tested my changes.

[rsp4jack]

https://github.com/EmbeddedSynth/sonivox/actions/runs/21965245212/job/63453251386?pr=20

At Configure CMake step:

cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_INSTALL_PREFIX=SonivoxV4 -DDEPENDENCY_DIRS=C:\msys64/mingw64/bin -DCPACK_SYSTEM_NAME=mingw64 -DINSTALL_DEPENDENCIES=ON

-- DEPENDENCY_DIRS: C:msys64/mingw64/bin

Does it actually work? If not, cygpath should also be used for DEPENDENCY_DIRS.

[pedrolcl]

Thanks for the heads up!

-- DEPENDENCY_DIRS: C:msys64/mingw64/bin

Does it actually work? If not, cygpath should also be used for DEPENDENCY_DIRS.

The NSIS installer program created by cpack does indeed work:
https://github.com/EmbeddedSynth/sonivox/actions/runs/21965245212/artifacts/5490438127

but anyway, I've pushed another commit transforming DEPENDENCY_DIRS with cygpath. This is used by CMake to resolve dependencies (in this case, zlib only) and I believe that works even if not specified or invalid, because it is in the $PATH.