The ornamental design for a hoofboot, as shown and described.
FIG. 1 is a perspective view of a hoof boot;
FIG. 2 is a toe view thereof;
FIG. 3 is a heel view thereof;
FIG. 4 is a first side view thereof;
FIG. 5 is a second side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines are directed to environment; the broken lines form no part of the claimed design.