Pin runner build SDK to 8.0.421 to mitigate macOS arm64 Process.Start deadlock in 2.336.0 - #4572

Pin runner build SDK to 8.0.421 to mitigate macOS arm64 Process.Start deadlock in 2.336.0#4572

TingluoHuang with Copilot wants to merge 2 commits into

mainactions/runner:mainfrom

copilot/fix-macos-runner-deadlockactions/runner:copilot/fix-macos-runner-deadlockCopy head branch name to clipboard