As a general rule: Do what you have to do. If you don’t need it; don’t do it.
For a minimal warm-up I would jog one or two laps to get the body temperature up and roll the joints so that they will move more easily.
Maybe some stretching is needed if you are stiff.
Personally I like to do some sprint drills too, like a,b skip and a-running. It feels like I have a better running posture after doing those.
Generally I’m a bit split about warm-up.
I think that warming up is very important, especially before high intense work, like a meet.
But sometimes I think it takes time and focus away from the real work.
Theoretically I think some light stretching and some walking would be good enough for any session.
Charlie Francis on Warm Ups: