feat: add gh-aw.agent.execute OpenTelemetry span around agentic engine execution#24654

Copilot wants to merge 2 commits intomaingithub/gh-aw:mainfrom

copilot/add-opentelemetry-span-agentic-enginegithub/gh-aw:copilot/add-opentelemetry-span-agentic-engineCopy head branch name to clipboard