No, being in a wheelchair will not impact your chances of getting residency overseas. There is often a medical exam required as a part of the residency process, but it’s a formality.
The only conditions that preclude residency in some countries are tuberculosis and certain transmittable blood diseases. In fact, many countries give preferential treatment to those with mobility issues or other additional needs, including fee waivers, fee reductions, lower thresholds of qualification, and expanded allowances for dependent visas.