I claim the ornamental design for footwear, as shown and described.
FIG. 1 is a front perspective view of footwear, showing my new design;
FIG. 2 is a right side view thereof; and,
FIG. 3 is a rear perspective view thereof.
The dashed lines illustrate unclaimed environmental structure. The dash dot dash lines immediately adjacent the solid-line portions of the footwear form the boundary and are not a part of the claimed design.