WebGPU on Windows (#10890)

* WebGPU on Windows

* Fix dawn-python install

* New test

* pydeps

* Minor fix

* Only install dawn-python on windows webgpu

---------

Co-authored-by: George Hotz <[email protected]>

.github/workflows/test.yml

@@ -938,7 +938,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        backend: [llvm, cpu]
+        backend: [llvm, cpu, webgpu]
 
     name: Windows (${{ matrix.backend }})
     runs-on: windows-latest
@@ -951,11 +951,12 @@ jobs:
       - name: Setup Environment
         uses: ./.github/actions/setup-tinygrad
         with:
-          key: windows-minimal
+          key: windows-${{ matrix.backend }}-minimal
           deps: testing_unit
+          pydeps: ${{ matrix.backend == 'webgpu' && 'dawn-python' || '' }}
       - name: Set env
         shell: bash
-        run:  printf "${{ matrix.backend == 'llvm' && 'LLVM=1' || matrix.backend == 'cpu' && 'CPU=1'}}" >> $GITHUB_ENV
+        run:  printf "${{ matrix.backend == 'llvm' && 'LLVM=1' || matrix.backend == 'cpu' && 'CPU=1' || matrix.backend == 'webgpu' && 'WEBGPU=1'}}" >> $GITHUB_ENV
       - name: Run unit tests
         if: matrix.backend=='llvm'
         run: python -m pytest -n=auto test/unit/ --ignore=test/unit/test_disk_tensor.py --ignore=test/unit/test_elf.py --ignore=test/unit/test_tar.py