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If you have access to a run out dial check to see if your rotor is warped. If you don't you can try pulling the caliper off and inspecting the pads. Is there a shiny worn spot on the edges of the pads? Does the caliper move freely in the bracket? Do the pads or rotor have a shiny glazed look?
Same principal as drum brakes just different components.
If the rotor is warped then the caliper has to oscillate with the warp. That makes it rub up against the bracket and could cause noise. Simple diagnostic is to LIGHTLY apply a heavy weight grease like you can get in little packets at the parts counter to all the places metal meets metal on the caliper. BE VERY CAREFUL to keep the grease off your fingers and the pads and rotor. While doing that crack the bleed valve and push the cylinder all the way back in, It should move smoothly. If not then maybe the caliper is locking up. Be sure to retighten the bleed valve. Put it back together and pumpt the brake pedal. Check that the cylinder actually moved back to put pressure on the pads. Reinstall the tire and see if it still squeeks.