I hear a squeeky sound from the drivers-side of my Jeep GC when driving.

It's most likely a wear indicator that is making this sound . A small tab of metal attached to one or both brake pads front or rear, not drum brakes, that rub against the rotors surface, sort of like fingernails on a chalk board. That is placed at a measured depth parallel with the pads travel as an indication when the pad has reached its service limit by emitting an audible sound. A annoying hard to ignore, tho some do, squeak. Good luck with that an have them checked out soon before you cost your self more parts/money.