Python type cleanup

Author: SteveSandersonMS

python/copilot/session.py

@@ -328,23 +328,25 @@ async def _execute_tool_and_respond(
             if inspect.isawaitable(result):
                 result = await result
 
+            tool_result: ToolResult
             if result is None:
-                result = ToolResult(
+                tool_result = ToolResult(
                     text_result_for_llm="Tool returned no result.",
                     result_type="failure",
                     error="tool returned no result",
                     tool_telemetry={},
                 )
-
+            else:
+                tool_result = result  # type: ignore[assignment]
 
             await self.rpc.tools.handle_pending_tool_call(
                 SessionToolsHandlePendingToolCallParams(
                     request_id=request_id,
                     result=ResultResult(
-                        text_result_for_llm=result.text_result_for_llm,
-                        error=result.error,
-                        result_type=result.result_type,
-                        tool_telemetry=result.tool_telemetry,
+                        text_result_for_llm=tool_result.text_result_for_llm,
+                        error=tool_result.error,
+                        result_type=tool_result.result_type,
+                        tool_telemetry=tool_result.tool_telemetry,
                     ),
                 )
             )