Merge pull request #37799 from giraffate/make_an_extra_file_in_testing_for_sqlite3_in_local

Fix making an extra db file after testing for sqlite3

activerecord/test/cases/connection_adapters/connection_handlers_multi_pool_config_test.rb

@@ -11,7 +11,7 @@ module ActiveRecord
       fixtures :people
 
       def setup
-        @writing_handler = ActiveRecord::Base.connection_handlers[:writing]
+        @writing_handler = ConnectionHandler.new
       end
 
       def teardown