Fix flaky tests:

- Some tests modify the `ActiveRecord.default_timezone` which
  has an influence on column information. It used to work before
  because the type (.e.g Type::DateTime) was not included in the
  Column object. Now that the type is included and that a Column
  is cached, we'd grab whatever type was in the cached column.

  So we have to force a reloading of the schema cache in order
  for whenver `ActiveRecord.default_timezone` is modified.

activerecord/test/cases/base_test.rb

@@ -1982,4 +1982,12 @@ def test_protected_environments_are_stored_as_an_array_of_string
       assert_not ActiveRecord::Base.current_preventing_writes
     end
   end
+
+  private
+    def with_timezone_config(cfg, &block)
+      super(cfg) do
+        Default.reset_column_information
+        block.call
+      end
+    end
 end