test: fix more array tests

ibis/backends/tests/test_array.py

@@ -604,9 +604,7 @@ def test_array_position(backend, con, a, expected_array):
     expr = t.a.index(42)
     result = con.execute(expr)
     expected = pd.Series(expected_array, dtype="object")
-    assert frozenset(map(tuple, result.values)) == frozenset(
-        map(tuple, expected.values)
-    )
+    assert frozenset(result.values) == frozenset(expected.values)
 
 
 @builtin_array
@@ -750,12 +748,10 @@ def test_array_union(con, a, b, expected_array):
     expr = t.a.union(t.b)
     result = con.execute(expr).map(set, na_action="ignore")
     expected = pd.Series(expected_array, dtype="object")
-    assert len(result) == len(expected)
 
-    result.sort_values()
-    expected.sort_values()
-    for i, (lhs, rhs) in enumerate(zip(result, expected)):
-        assert lhs == rhs, f"row {i:d} differs"
+    assert frozenset(map(tuple, result.values)) == frozenset(
+        map(tuple, expected.values)
+    )
 
 
 @builtin_array