[TST] Fix test_quantile_interpolation_int (pandas-dev#26633)

Author: makbigc

pandas/tests/frame/test_quantile.py

@@ -160,8 +160,7 @@ def test_quantile_interpolation_int(self, int_frame):
         assert q['A'] == np.percentile(df['A'], 10)
 
         # test with and without interpolation keyword
-        # TODO: q1 is not different from q
-        q1 = df.quantile(0.1)
+        q1 = df.quantile(0.1, axis=0, interpolation='linear')
         assert q1['A'] == np.percentile(df['A'], 10)
         tm.assert_series_equal(q, q1)