[Catalog] Silently ignore TPU price not found. (skypilot-org#4134)

* [Catalog] Silently ignore TPU price not found.

* assert for non tpu v6e

* format

sky/clouds/service_catalog/data_fetchers/fetch_gcp.py

@@ -681,7 +681,13 @@ def get_tpu_price(row: pd.Series, spot: bool) -> Optional[float]:
             spot_str = 'spot ' if spot else ''
             print(f'The {spot_str}price of {tpu_name} in {tpu_region} is '
                   'not found in SKUs or hidden TPU price DF.')
-        assert spot or tpu_price is not None, (row, hidden_tpu, HIDDEN_TPU_DF)
+        # TODO(tian): Hack. Should investigate how to retrieve the price
+        # for TPU-v6e.
+        if not tpu_name.startswith('tpu-v6e'):
+            assert spot or tpu_price is not None, (row, hidden_tpu,
+                                                   HIDDEN_TPU_DF)
+        else:
+            tpu_price = 0.0
         return tpu_price
 
     df['Price'] = df.apply(lambda row: get_tpu_price(row, spot=False), axis=1)