removed client a thin interface

Author: asheshvidyut

src/mcp/client/transport_session.py

@@ -80,16 +80,6 @@ async def call_tool(
         """Send a tools/call request with optional progress callback support."""
         raise NotImplementedError
 
-    @abstractmethod
-    async def _validate_tool_result(
-        self,
-        name: str,
-        result: types.CallToolResult,
-    ) -> None:
-        """Validate the structured content of a tool result against its output
-        schema."""
-        raise NotImplementedError
-
     @abstractmethod
     async def list_prompts(
         self,