Rails - Skip data_migrations in specific environments

I am writing a data_migration for which I am using data-migrate gem. I have a situation where I should skip one specific data_migration in Production environment alone. I can do it like this

class BackfillNonStatutoryResultsWithAssessmentPeriod < ActiveRecord::Migration[7.0]
  def up 
    unless RAILS_ENV == "production"
     # Do something
    end
  end
end
 def down
   raise ActiveRecord::IrreversibleMigration
  end
end

What is the best and efficient way to achieve this?

I think your code looks fine, but I would improve it a little bit

class BackfillNonStatutoryResultsWithAssessmentPeriod < ActiveRecord::Migration[7.0]
  def up
    return if Rails.env.production?
    # Do something
  end
  def down
   raise ActiveRecord::IrreversibleMigration
  end
end

Never used the gem before, but the README seems to be clear that this gem's whole purpose is to enable you to have a separate rake task for migrating with data vs just schema:

> For setting tasks that don't require any intermediate AR activity, like dev and test, you stick with db:migrate. For production and QA, you change their scripts to db:migrate:with_data.

If you're having an issue with that then it's not clear from your question.