[Rails5] uninitialized constant ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter::MysqlDateTime

Note: add rails5 to a branch name to trigger rails5 specific CI jobs.

https://gitlab.com/gitlab-org/gitlab-ce/-/jobs/67730808

NameError: uninitialized constant ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter::MysqlDateTime
/builds/gitlab-org/gitlab-ce/config/initializers/active_record_data_types.rb:68:in `<class:AbstractMysqlAdapter>'
/builds/gitlab-org/gitlab-ce/config/initializers/active_record_data_types.rb:64:in `<top (required)>'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/engine.rb:648:in `block in load_config_initializer'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/activesupport-5.0.7/lib/active_support/notifications.rb:166:in `instrument'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/engine.rb:647:in `load_config_initializer'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/engine.rb:612:in `block (2 levels) in <class:Engine>'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/engine.rb:611:in `each'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/engine.rb:611:in `block in <class:Engine>'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/initializable.rb:30:in `instance_exec'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/initializable.rb:30:in `run'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/initializable.rb:55:in `block in run_initializers'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/initializable.rb:44:in `each'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/initializable.rb:44:in `tsort_each_child'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/initializable.rb:54:in `run_initializers'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/application.rb:352:in `initialize!'
/builds/gitlab-org/gitlab-ce/config/environment.rb:11:in `<top (required)>'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/application.rb:328:in `require_environment!'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/railties-5.0.7/lib/rails/application.rb:448:in `block in run_tasks_blocks'
/builds/gitlab-org/gitlab-ce/vendor/ruby/2.3.0/gems/rake-12.3.1/exe/rake:27:in `<top (required)>'
/usr/local/bin/bundle:23:in `load'
/usr/local/bin/bundle:23:in `<main>'