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 left side view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a front view thereof;
FIG. 5 is a back view thereof; and,
FIG. 6 is a top view thereof.
The broken line showing of the heel, heel cap, sole, and portions of the upper in the drawings depicts subject matter that forms no part of the claimed design.