fix(mcpserver): add lax no cover pragmas for subprocess-only coverage paths

Lines 306-308 (match transport/stdio case) and 860-867 (run_stdio_async)
are only covered via subprocess in test_1027_win_unreachable_cleanup.py.
Coverage 7.10.7 (lowest-direct) does not capture subprocess coverage on
Windows+Python 3.13, causing a spurious fail_under=100 failure.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Zelys-DFKH

src/mcp/server/mcpserver/server.py

@@ -303,7 +303,7 @@ def run(
         if transport not in TRANSPORTS.__args__:  # type: ignore  # pragma: no cover
             raise ValueError(f"Unknown transport: {transport}")
 
-        match transport:
+        match transport:  # pragma: lax no cover
             case "stdio":
                 anyio.run(self.run_stdio_async)
             case "sse":  # pragma: no cover
@@ -857,7 +857,7 @@ def decorator(  # pragma: no cover
 
         return decorator  # pragma: no cover
 
-    async def run_stdio_async(self) -> None:
+    async def run_stdio_async(self) -> None:  # pragma: lax no cover
         """Run the server using stdio transport."""
         async with stdio_server() as (read_stream, write_stream):
             await self._lowlevel_server.run(