Bumping version to 1.23.3

update ruby to 3.4.7

remove broken links

update urls in gemspec

drop ruby 2.6

Merge pull request #401 from hsbt/update-github-url

s/railsbp/flyerhzm/g

Merge pull request #398 from KeiSakam/fix-klass-at-the-end_class

Although exit from a class, current class can exists.

Bumping versio to 1.23.2

require_ruby_version 2.3.0

update ruby version to 3.1.2

Merge pull request #393 from mishina2228/fix-warnings

Update bundler

Replace coveralls with coveralls_reborn