fix: override end_turn stop reason when streaming response contains toolUse blocks#1827

atian8179 wants to merge 2 commits intostrands-agents:mainstrands-agents/sdk-python:mainfrom

atian8179:fix/streaming-tool-use-stop-reason-overrideatian8179/sdk-python:fix/streaming-tool-use-stop-reason-overrideCopy head branch name to clipboard