ci: remove swiftshader setup

the action exports `VK_DRIVER_FILES` on its own now: jakoch/install-vulkan-sdk-action#545

Author: Firestar99

.github/workflows/ci.yaml

@@ -169,12 +169,6 @@ jobs:
           # install_lavapipe: true
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      - if: ${{ runner.os == 'Windows' }}
-        name: Windows - Use SwiftShader as Vulkan driver
-        # FIXME(eddyb) ideally `jakoch/install-vulkan-sdk-action` should do this.
-        run: |
-          echo "C:/Swiftshader/" >> "$GITHUB_PATH"
-          echo "VK_DRIVER_FILES=C:/Swiftshader/vk_swiftshader_icd.json" >> "$GITHUB_ENV"
       - if: ${{ runner.os == 'Linux' }}
         name: Linux - Install native dependencies
         run: sudo apt install libwayland-cursor0 libxkbcommon-dev libwayland-dev