fix(mcp): reset stdio session stack state on cleanup#2461

OiPunk wants to merge 5 commits intoopenai:mainopenai/openai-agents-python:mainfrom

OiPunk:codex/openai-agents-618-mcp-stdio-semaphore-leak-fixOiPunk/openai-agents-python:codex/openai-agents-618-mcp-stdio-semaphore-leak-fixCopy head branch name to clipboard