Add dev env

[atm-snag2]

What

• add dev environment with Docker
• remove alias_method_chain
• put keyword only first select
• else
  • remove ActiveSupport 4.x support (cannot prepare environment for mysql2 0.3)
  • remove Ruby 2.6 support (2.6 cannot install activesupport 7.0)
  • pending support ActiveRecord 7.1 because Arproxy does not behave expectedly on it.
  • ActiveRecord 5.x cannot run on Ruby 3.x.
  • require Rake 12.3.2 for Ruby 3.3

Refs

• Component 'json' of Ruby on Rails not working with Ruby 2.4.0 rails/rails#27450
• Unable to install ruby gem brianmario/mysql2#1120
• Use ActiveRecord 7.1 with MySQL arproxy#1
• https://github.com/ruby/rake/releases/tag/v12.3.2

  • Fixed test fails caused by 2.6 warnings by @hsbt in Fixed test fails caused by 2.6 warnings  ruby/rake#297

• https://dev.mysql.com/doc/refman/5.7/en/select.html

  • these modifiers are not permitted in subqueries (including subqueries in the FROM clause), and SELECT statements in unions other than the first SELECT.