I claim the ornamental design for footwear, as shown and described.
FIG. 1 is a perspective view of footwear, showing my new design;
FIG. 2 is a left side view thereof; and,
FIG. 3 is a front view thereof.
The regular dashed lines are included for the purpose of illustrating portions of the footwear that form no part of the claimed design. The bold dash-dot-dash lines represent boundaries of the claimed design.