ci: fix import error from dask test (#737)

* ci: fix import error from dask test

* fix

tests/frame/add_test.py

@@ -1,14 +1,10 @@
 from typing import Any
 
-import pytest
-
 import narwhals.stable.v1 as nw
 from tests.utils import compare_dicts
 
 
-def test_add(constructor: Any, request: Any) -> None:
-    if "dask" in str(constructor):
-        request.applymarker(pytest.mark.xfail)
+def test_add(constructor: Any) -> None:
     data = {"a": [1, 3, 2], "b": [4, 4, 6], "z": [7.0, 8, 9]}
     df = nw.from_native(constructor(data))
     result = df.with_columns(

tests/translate/from_native_test.py

@@ -191,7 +191,7 @@ def test_series_only_dask() -> None:
 )
 def test_eager_only_lazy_dask(eager_only: Any, context: Any) -> None:
     pytest.importorskip("dask")
-    pytest.importorskip("dask_expr")
+    pytest.importorskip("dask_expr", exc_type=ImportError)
     import dask.dataframe as dd
 
     dframe = dd.from_pandas(df_pd)