P20-1549: Fix User.find_channel_owner test

[artem-vavilov]

Issue

=ERROR["test_find_channel_owner_returns_nil_for_channel_with_no_owner", "UserTest", 670.325951756]
740 | test_find_channel_owner_returns_nil_for_channel_with_no_owner#UserTest (670.33s)
741 | Minitest::UnexpectedError:         Sequel::DatabaseError: Mysql2::Error::TimeoutError: Timeout waiting for a response from the last query. (waited 30 seconds)
742 | test/testing/projects_test_utils.rb:31:in `with_storage_id_for'
743 | test/testing/projects_test_utils.rb:9:in `with_channel_for'
744 | test/testing/projects_test_utils.rb:35:in `with_anonymous_channel'
745 | test/models/user_test.rb:4246:in `block in <class:UserTest>'
746 | test/testing/setup_all_and_teardown_all.rb:36:in `run'

Links

• JIRA task: P20-1549
• Related PR: skip flaky unit test for channel with no owner #66713