Why are my bike's disc brakes squeaking and how can I fix this issue?

Your bike's disc brakes may be squeaking due to contamination, misalignment, or worn brake pads. To fix this issue, you can try cleaning the brake rotors and pads, adjusting the brake calipers for proper alignment, or replacing the brake pads if they are worn out. If the problem persists, it may be best to consult a professional bike mechanic for further assistance.