Update test_sparse.py

`test_fillna_no_op_returns_copy` now works for all cases in Pandas 3.0.0 without special casing.

Signed-off-by: Michael Tiemann <72577720+MichaelTiemannOSC@users.noreply.github.com>

Author: MichaelTiemannOSC

pandas/tests/extension/test_sparse.py

@@ -235,11 +235,6 @@ def test_isna(self, data_missing):
         tm.assert_equal(sarr.isna(), expected)
 
     def test_fillna_no_op_returns_copy(self, data, request):
-        # `data` never contains complex numbers in these tests
-        if np.isnan(data.fill_value):
-            request.applymarker(
-                pytest.mark.xfail(reason="returns array with different fill value")
-            )
         super().test_fillna_no_op_returns_copy(data)
 
     @pytest.mark.xfail(reason="Unsupported")