Fix stdio_server closing process stdio#2505

GitAashishG wants to merge 2 commits intomodelcontextprotocol:mainmodelcontextprotocol/python-sdk:mainfrom

GitAashishG:fix-1933-stdio-does-not-close-real-stdioGitAashishG/mcp-python-sdk:fix-1933-stdio-does-not-close-real-stdioCopy head branch name to clipboard