class Airbrake::Rails::Railties::ActiveRecordTie

def detect_activerecord_adapter(configurations)

`#[]`, so we need an updated call.
Rails 6+ introduces the `configs_for` API instead of the deprecated 
def detect_activerecord_adapter(configurations)
  unless configurations.respond_to?(:configs_for)
    return configurations[::Rails.env]['adapter']
  end
  cfg = configurations.configs_for(env_name: ::Rails.env).first
  # Rails 7+ API : Rails 6 API.
  cfg.respond_to?(:adapter) ? cfg.adapter : cfg.config['adapter']
end