modify join test to check for overlapping column names

tests/test_common.py

@@ -173,7 +173,7 @@ def test_rename(df_raw: Any) -> None:
 @pytest.mark.parametrize("df_raw", [df_pandas, df_lazy])
 def test_join(df_raw: Any) -> None:
     df = nw.LazyFrame(df_raw)
-    df_right = df.rename({"z": "z_right"})
+    df_right = df
     result = df.join(df_right, left_on=["a", "b"], right_on=["a", "b"], how="inner")
     result_native = nw.to_native(result)
     expected = {"a": [1, 3, 2], "b": [4, 4, 6], "z": [7.0, 8, 9], "z_right": [7.0, 8, 9]}