fix(langchain): langchain end span

packages/opentelemetry-instrumentation-langchain/opentelemetry/instrumentation/langchain/callback_handler.py

@@ -181,11 +181,14 @@ def _end_span(self, span: Span, run_id: UUID) -> None:
             child_span = self.spans[child_id].span
             if child_span.end_time is None:  # avoid warning on ended spans
                 child_span.end()
+                self.spans.pop(child_id, None)
         span.end()
         token = self.spans[run_id].token
         if token:
             context_api.detach(token)
 
+        self.spans.pop(run_id, None)
+
     def _create_span(
         self,
         run_id: UUID,