test: xfail polars>1.7.0 Expr.mode with broadcast (#953)

* fix: xfail polars expr mode

* use parse_version

tests/expr_and_series/mode_test.py

@@ -1,8 +1,10 @@
 from typing import Any
 
+import polars as pl
 import pytest
 
 import narwhals.stable.v1 as nw
+from narwhals.utils import parse_version
 from tests.utils import compare_dicts
 
 data = {
@@ -22,7 +24,9 @@ def test_mode_single_expr(constructor: Any, request: Any) -> None:
 
 
 def test_mode_multi_expr(constructor: Any, request: Any) -> None:
-    if "dask" in str(constructor):
+    if "dask" in str(constructor) or (
+        "polars" in str(constructor) and parse_version(pl.__version__) >= (1, 7, 0)
+    ):
         request.applymarker(pytest.mark.xfail)
     df = nw.from_native(constructor(data))
     result = df.select(nw.col("a", "b").mode()).sort("a", "b")