Finish email allow/deny list naming migration (#30530)

.rubocop_todo.yml

app/models/user.rb

app/validators/email_mx_validator.rb

app/validators/user_email_validator.rb

app/workers/scheduler/auto_close_registrations_scheduler.rb

config/initializers/blacklists.rb

config/initializers/doorkeeper.rb

config/initializers/email_domains_lists.rb

spec/models/user_spec.rb

spec/validators/email_mx_validator_spec.rb

spec/validators/user_email_validator_spec.rb