The ornamental design for footwear, as shown and described.
FIG. 1 is a front perspective view of the footwear showing my new design;
FIG. 2 is a left side view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a front view thereof; and,
FIG. 5 is a top view thereof.
The broken line showing of the heel, sole, heel cap, portions of the straps, footbed, grommets and rivets of the footwear is for illustrative purposes only and forms no part of the claimed design.