BaseTools/Plugin/WindowsVsToolChain: Add WindowsSDKLibVersion

Fix VS20xx build failures in GitHub Actions windows-2025
environments due to missing libraries.

Add WindowsSDKLibVersion to the set of environment variables
that are set in a Windows Visual Studio build environment.

WindowsSDKLibVersion is required to set LIBPATH for VS20xx
builds of the EmulatorPkg and Host-based unit tests.

Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>