Make Index Join Tests on Default Precisions Deterministic (#11451)

This PR fixes a flaky test introduced by #11272, cudf joins by default does not guarantee return orders and may lead to occasional test regression. This PR adds `sort` argument to make sure result is deterministic.

Note that `index.union` and `index.intersection` may also include random output ordering, but by default these methods sorts the result before returning so `sort` argument does not need to be modified.

Authors:
   - Michael Wang (https://github.com/isVoid)

Approvers:
   - GALI PREM SAGAR (https://github.com/galipremsagar)
   - https://github.com/brandon-b-miller
   - Nghia Truong (https://github.com/ttnghia)

python/cudf/cudf/tests/test_index.py

@@ -2674,7 +2674,7 @@ def test_rangeindex_join_user_option(default_integer_bitwidth):
     idx1 = cudf.RangeIndex(0, 10)
     idx2 = cudf.RangeIndex(5, 15)
 
-    actual = idx1.join(idx2, how="inner")
+    actual = idx1.join(idx2, how="inner", sort=True)
     expected = cudf.Index(
         [5, 6, 7, 8, 9], dtype=f"int{default_integer_bitwidth}", name=0
     )