Handle bot string and numeric epoch values

Signed-off-by: Anuradha Karuppiah <26330987+AnuradhaKaruppiah@users.noreply.github.com>

Author: AnuradhaKaruppiah

packages/nvidia_nat_profiler/src/nat/plugins/profiler/runtime_evaluator/atif_evaluate.py

@@ -52,7 +52,12 @@ async def evaluate_atif_item(self, sample: AtifEvalSample) -> EvalOutputItem:
             end_ts = _iso_to_epoch(step.timestamp)
             ancestry = (step.extra or {}).get("ancestry")
             start_ts_raw = ancestry.get("span_event_timestamp") if isinstance(ancestry, dict) else None
-            start_ts = _iso_to_epoch(start_ts_raw) if isinstance(start_ts_raw, str) else None
+            if isinstance(start_ts_raw, (int, float)):
+                start_ts = float(start_ts_raw)
+            elif isinstance(start_ts_raw, str):
+                start_ts = _iso_to_epoch(start_ts_raw)
+            else:
+                start_ts = None
             if end_ts is not None and start_ts is not None:
                 latencies.append(max(0.0, end_ts - start_ts))