Report tcnn import errors (#1969)

tests/field_components/test_fields.py

@@ -11,7 +11,7 @@ def test_tcnn_instant_ngp_field():
     """Test the tiny-cuda-nn field"""
     try:
         import tinycudann as tcnn  # noqa: F401
-    except ImportError as e:
+    except ModuleNotFoundError as e:
         # tinycudann module doesn't exist
         print(e)
         return