[fix] Apply patch for hanging process issue on test completion

[steviec]

Problem: Users reported that mcp-server-tester would complete all tests successfully but the process wouldn't exit, requiring Ctrl+C to terminate.

Root cause: The @modelcontextprotocol/sdk's StdioClientTransport.close() method wasn't properly terminating child processes when servers ignored shutdown signals.

This is a known issue and there's 3 open PRs in the sdk repo to fix it!

Solution: Applied patch from typescript-sdk PR #821 that implements graceful shutdown:

• Closes stdin and waits 100ms for natural exit
• Sends SIGTERM and waits 1 second
• Sends SIGKILL as last resort

This ensures child processes are properly cleaned up, allowing the test runner to exit normally.

Patch will be automatically applied via patch-package on npm install until the official fix is released.