FIG. 1 is a bottom perspective view of my ornamental design of a footwear outsole;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines and areas enclosed within them depict portions of the footwear outsole that form no part of the claimed design.