fix: add pragma no-cover to defensive except-Exception fallback

The except-Exception block in _handle_call_tool is now a defensive
catch-all: Tool.run() wraps all non-ToolError exceptions in ToolError,
so this path is only reachable if call_tool is overridden by a subclass.
This matches the existing pragma pattern used throughout the file.

Author: blackwell-systems

src/mcp/server/mcpserver/server.py

@@ -316,7 +316,7 @@ async def _handle_call_tool(
             if e.content is not None:
                 return CallToolResult(content=e.content, is_error=True)
             return CallToolResult(content=[TextContent(type="text", text=str(e))], is_error=True)
-        except Exception as e:
+        except Exception as e:  # pragma: no cover
             return CallToolResult(content=[TextContent(type="text", text=str(e))], is_error=True)
         if isinstance(result, CallToolResult):
             return result