ci : try adding CMake CUDA compiler toolchain file

Author: danbev

.github/workflows/build.yml

@@ -126,12 +126,11 @@ jobs:
           echo "SDL2_DIR=${{ github.workspace }}\SDL2-${{ matrix.sdl2_ver }}\cmake" | Out-File -FilePath $env:GITHUB_ENV -Append
           echo "${{ github.workspace }}\SDL2-${{ matrix.sdl2_ver }}\cmake" > SDL2_PATH.txt
 
-      - name: Create nvcc wrapper for sccache
+      - name: Create CMake CUDA compiler toolchain file
         shell: cmd
         run: |
-          echo @echo off > nvcc-sccache.bat
-          echo sccache "%CUDA_PATH%\bin\nvcc.exe" %%* >> nvcc-sccache.bat
-          echo set CUDA_NVCC_EXECUTABLE=%CD%\nvcc-sccache.bat >> %GITHUB_ENV%
+          echo SET(CMAKE_CUDA_COMPILER_LAUNCHER sccache) > cuda_toolchain.cmake
+          echo SET(CMAKE_CUDA_COMPILER "%CUDA_PATH%/bin/nvcc.exe") >> cuda_toolchain.cmake
 
       - name: Configure CMake
         shell: cmd
@@ -140,10 +139,10 @@ jobs:
           set "CUDACXX=sccache %CUDA_PATH%\bin\nvcc.exe"
           cmake -S . -B ./build -A ${{ matrix.arch }} ^
             -DCMAKE_BUILD_TYPE=${{ matrix.build }} ^
+            -DCMAKE_TOOLCHAIN_FILE=cuda_toolchain.cmake ^
             -DGGML_CUDA=${{ matrix.cublas }} ^
             -DCMAKE_CUDA_ARCHITECTURES=all  ^
             -DWHISPER_SDL2=${{ matrix.sdl2 }} ^
-            -DCMAKE_CUDA_COMPILER="%CD%\nvcc-sccache.bat" ^
             -DCMAKE_CUDA_COMPILER_LAUNCHER=sccache ^
             -DCMAKE_C_COMPILER_LAUNCHER=sccache ^
             -DCMAKE_CXX_COMPILER_LAUNCHER=sccache ^