Clear query cache for QueryCacheExpiryTest as well

- This solves failure of order dependent tests when tests from
  QueryCacheExpiryTest class are run before the tests from
  QueryCacheTest class.
- In above scenario, the warmed cache created by tests from
  QueryCacheExpiryTest class is never cleared before running first test
  from QueryCacheTest class. So first test from QueryCacheTest class was
  always failing.
- Reproduction `bundle exec ruby -Itest test/cases/query_cache_test.rb --seed 60165 -v`

Author: prathamesh-sonpatki

activerecord/test/cases/query_cache_test.rb

@@ -388,6 +388,10 @@ def assert_cache(state, connection = ActiveRecord::Base.connection)
 class QueryCacheExpiryTest < ActiveRecord::TestCase
   fixtures :tasks, :posts, :categories, :categories_posts
 
+  teardown do
+    Task.connection.clear_query_cache
+  end
+
   def test_cache_gets_cleared_after_migration
     # warm the cache
     Post.find(1)