Fix Windows CI by removing unsupported CMAKE_BUILD_TYPE usage

[tomoss]

Hello,

This follow-up PR removes the -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
argument from the Windows CI configuration.

MSVC uses a multi-config generator, so CMAKE_BUILD_TYPE is ignored and
produces a warning during configuration. The workflow already relies on
--config <type> during the build step, which is the correct approach.

Sorry for not including this cleanup in the previous PR.

[max0x7ba]

Thank you Ionut. I admire your attention to details.