Fix flaky test in HasManyThroughDisableJoinsAssociationsTest

[DmitryTsepelev]

Summary

While working on #38957 I got the HasManyThroughDisableJoinsAssociationsTest#test_to_a_on_disable_joins_with_multiple_scopes sometimes failing in PSQL suite, which's weird since I do not even touch AR:

Failure:
HasManyThroughDisableJoinsAssociationsTest#test_to_a_on_disable_joins_with_multiple_scopes [/rails/activerecord/test/cases/associations/has_many_through_disable_joins_associations_test.rb:124]:
--- expected
+++ actual
@@ -1 +1 @@
-[#<Rating id: 6, comment_id: 16, value: 8>, #<Rating id: 7, comment_id: 16, value: 9>]
+[#<Rating id: 7, comment_id: 16, value: 9>, #<Rating id: 6, comment_id: 16, value: 8>]

PostgreSQL does not guarantee the order of records and we never specify it. I wonder if adding an explicit order is fine or it makes the spec itself wrong.

[gmcgibbon]

de6b4ef, https://buildkite.com/rails/rails/builds/82494#e482cf73-ee6a-42eb-9efa-13c04d84cc14

I believe the assertion is related to query count more than order. LGTM 👍