Use clang for Windows builds

Author: czgdp1807

.github/workflows/ci.yml

@@ -193,12 +193,13 @@ jobs:
       - name: Install clang
         run: |
           choco install llvm -y
+          echo "C:\\Program Files\\LLVM\\bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
 
       - name: Build package
         env:
           CC: clang-cl
           CXX: clang-cl
-          CXXFLAGS: "-std=c++17"
+          CL: "/std:c++17"
         run: |
           python scripts/build/install.py