fix: add pragma for unused list_tools handler

The handler is required by the Server class but never invoked
in these tests (only initialize() is called).

Github-Issue:#1641

Author: skyvanguard

tests/issues/test_1641_accept_header_wildcard.py

@@ -45,7 +45,7 @@ def __init__(self):
         super().__init__(SERVER_NAME)
 
         @self.list_tools()
-        async def handle_list_tools() -> list[Tool]:
+        async def handle_list_tools() -> list[Tool]:  # pragma: no cover
             return []