fix mypy

Author: nimarb

langfuse/_client/client.py

@@ -1660,7 +1660,7 @@ def update_current_trace(
         current_otel_span = self._get_current_otel_span()
 
         if current_otel_span is not None:
-            existing_observation_type = current_otel_span.attributes.get(
+            existing_observation_type = current_otel_span.attributes.get(  # type: ignore[attr-defined]
                 LangfuseOtelSpanAttributes.OBSERVATION_TYPE, "span"
             )
             # We need to preserve the class to keep the corret observation type

langfuse/_client/span.py

@@ -1465,11 +1465,9 @@ def start_as_current_generation(
             DeprecationWarning,
             stacklevel=2,
         )
-        return cast(
-            _AgnosticContextManager["LangfuseGeneration"],
-            self.start_as_current_observation(
-                name=name,
-                as_type="generation",
+        return self.start_as_current_observation(
+            name=name,
+            as_type="generation",
                 input=input,
                 output=output,
                 metadata=metadata,
@@ -1482,8 +1480,7 @@ def start_as_current_generation(
                 usage_details=usage_details,
                 cost_details=cost_details,
                 prompt=prompt,
-            ),
-        )
+            )
 
     def create_event(
         self,