Are there regulations that limit the airports an air carrier can visit based on rescue equipment?
For at least part 121 operations supported by part 139 certified airports or 139 airports that have unscheduled passenger traffic in aircraft capable of carrying more than 31 passengers; yes


  Operators of Part 139 airports must provide aircraft rescue and
  firefighting (ARFF) services during air carrier operations that
  require a Part 139 certificate. The guidance and resources below
  address ARFF training, ARFF vehicles, and other aviation fire and
  rescue requirements.