I want to turn this off but I can’t think of how this is happening in the first place.
Alternatively maybe barometer? All modern iPhones have one, but I don't know if apps are allowed to access it in the background (or without location services), and it wouldn't let Lyft tell which airport you were at.
The app might pull accelerometer data in a way that suggests you just landed or were on a plane? Could it be that the cell towers in that area are known to be based at the airport?