ci: change upload-artifact & download-artifact to Cysharp/Actions

Author: guitarrapc

.github/workflows/build-release.yml

@@ -28,7 +28,7 @@ jobs:
       - run: dotnet test -c Release --no-build
       - run: dotnet pack -c Release --no-build -p:Version=${{ inputs.tag }} -o ./publish
       # Store artifacts.
-      - uses: actions/upload-artifact@v2
+      - uses: Cysharp/Actions/.github/actions/upload-artifact@main
         with:
           name: nuget
           path: ./publish/