Make external Vulkan backend optional

.github/workflows/workflow.yml

@@ -96,19 +96,6 @@ jobs:
             Directory.Packages.props
             Directory.Build.props
 
-      - name: Install Windows native GPU dependencies
-        shell: pwsh
-        run: |
-          & "$env:VCPKG_INSTALLATION_ROOT\vcpkg.exe" install sdl3[vulkan]:x64-windows vulkan:x64-windows
-
-          cmake `
-            -S src/SharpEmu.Gpu.Vulkan.Native `
-            -B artifacts/native/gpu-vulkan `
-            -A x64 `
-            -DCMAKE_TOOLCHAIN_FILE="$env:VCPKG_INSTALLATION_ROOT/scripts/buildsystems/vcpkg.cmake" `
-            -DVCPKG_TARGET_TRIPLET=x64-windows `
-            -DBUILD_TESTING=OFF
-
       - name: Restore solution
         run: dotnet restore SharpEmu.slnx
 
@@ -127,19 +114,6 @@ jobs:
       - name: Publish win-x64 CLI
         run: dotnet publish src/SharpEmu.CLI/SharpEmu.CLI.csproj -c Release -r win-x64 --self-contained true --no-restore -p:PublishDir="${env:PUBLISH_DIR}"
 
-      - name: Verify Windows native GPU runtime
-        shell: pwsh
-        run: |
-          $required = @(
-            (Join-Path $env:PUBLISH_DIR 'sharpemu_gpu_vulkan.dll'),
-            (Join-Path $env:PUBLISH_DIR 'SDL3.dll')
-          )
-          foreach ($path in $required) {
-            if (-not (Test-Path $path)) {
-              throw "Missing native GPU runtime: $path"
-            }
-          }
-
       - name: Create release archive
         run: |
           New-Item -ItemType Directory -Path $env:RELEASE_DIR -Force | Out-Null
@@ -191,42 +165,6 @@ jobs:
             Directory.Packages.props
             Directory.Build.props
 
-      - name: Install Linux native GPU dependencies
-        if: matrix.rid == 'linux-x64'
-        run: |
-          sudo apt-get update
-          sudo apt-get install --yes \
-            autoconf \
-            autoconf-archive \
-            automake \
-            libegl1-mesa-dev \
-            libibus-1.0-dev \
-            libtool \
-            libltdl-dev \
-            libvulkan-dev \
-            libwayland-dev \
-            libxkbcommon-dev \
-            pkg-config
-          "$VCPKG_INSTALLATION_ROOT/vcpkg" install sdl3[vulkan]:x64-linux
-          cmake \
-            -S src/SharpEmu.Gpu.Vulkan.Native \
-            -B artifacts/native/gpu-vulkan \
-            -DCMAKE_BUILD_TYPE=Release \
-            -DCMAKE_TOOLCHAIN_FILE="$VCPKG_INSTALLATION_ROOT/scripts/buildsystems/vcpkg.cmake" \
-            -DVCPKG_TARGET_TRIPLET=x64-linux \
-            -DBUILD_TESTING=OFF
-
-      - name: Install macOS native GPU dependencies
-        if: matrix.rid == 'osx-x64'
-        run: |
-          brew install sdl3 vulkan-loader vulkan-headers
-          cmake \
-            -S src/SharpEmu.Gpu.Vulkan.Native \
-            -B artifacts/native/gpu-vulkan \
-            -DCMAKE_BUILD_TYPE=Release \
-            -DCMAKE_PREFIX_PATH="$(brew --prefix)" \
-            -DBUILD_TESTING=OFF
-
       - name: Restore solution
         run: dotnet restore SharpEmu.slnx