Switch to use bash on Windows.

Author: jcant0n

.github/workflows/meshopt-cmake.yml

@@ -71,11 +71,12 @@ jobs:
             -DCMAKE_OSX_ARCHITECTURES=${{ matrix.cmake-arch }}
 
       - name: Configure meshoptimizer (Windows)
-        if: matrix.os == 'windows-latest'
-        run: |
-          cmake -S . -B build \
-            -A ${{ matrix.cmake-arch }} \
-            -DMESHOPT_BUILD_SHARED_LIBS=ON
+         if: matrix.os == 'windows-latest'
+         shell: bash
+         run: |
+           cmake -S . -B build \
+             -A ${{ matrix.cmake-arch }} \
+             -DMESHOPT_BUILD_SHARED_LIBS=ON
 
       - name: Build meshoptimizer
         run: cmake --build build --config Release