#644 introduced MigrationClassName which doesn't play along with rails generated migrations for ActiveStorage

Issue with rails generated active storage migrations.

db/migrate/20210214101402_create_active_storage_tables.active_storage.rb:2:7: C: [Correctable] Rails/MigrationClassName: Replace with CreateActiveStorageTables.activeStorage that matches the file name.

where CreateActiveStorageTables.activeStorage is an invalid syntax. The cop should exclude activestorage migration files

RuboCop version

$ [bundle exec] rubocop -V
1.26.0 (using Parser 3.1.1.0, rubocop-ast 1.16.0, running on ruby 3.1.1 arm64-darwin21)
  - rubocop-performance 1.13.3
  - rubocop-rails 2.14.0
  - rubocop-rspec 2.9.0