The ornamental design for footwear, as shown and described.
FIG. 1 is a front perspective view.
FIG. 2 is a front view.
FIG. 3 is a back view.
FIG. 4 is an outer side view.
FIG. 5 is an inner side view.
FIG. 6 is a top view; and,
FIG. 7 is a bottom view.
The broken line showing of the sole, upper, and surface treatment thereof is for illustrative purpose only and forms no part of the claimed design.