[CI] pass the correct environment variable to CMAKE_Fortran_COMPILER …

…in Windows build

.github/workflows/build-windows.yml

@@ -42,7 +42,7 @@ jobs:
     - name: Configure CMake
       # Configure CMake in a 'build' subdirectory. `CMAKE_BUILD_TYPE` is only required if you are using a single-configuration generator such as make.
       # See https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html?highlight=cmake_build_type
-      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} -DCMAKE_Fortran_COMPILER=$FC
+      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} -DCMAKE_Fortran_COMPILER=${{env.FC}}
 
     - name: Build
       # Build your program with the given configuration