use cmd shell to setup build

Author: mattip

.github/workflows/windows.yml

@@ -81,14 +81,16 @@ jobs:
         echo CIBW_ENVIRONMENT_WINDOWS=$env:CIBW_ENVIRONMENT_WINDOWS
 
     - name: Build
+      shell: cmd
       run: |
-        if ( "${{ matrix.plat }}" -eq "arm64") {
+        if "${{ matrix.plat }}" == "arm64" (
             echo Setting up ARM64 Developer Command Prompt
             CALL "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvarsarm64.bat"
+            if errorlevel 1 exit /b 1
             PATH=C:\Program Files\LLVM\bin;%PATH%
-        }
+        )
         git submodule update --init --recursive
-        & $env:BASH_PATH -lc tools/build_steps_windows.sh
+        %BASH_PATH% -lc tools/build_steps_windows.sh
 
     - name: Test
       run: |