The ornamental design for a seat, as shown and described.
FIG. 1 is a front, top and right sides perspective view of a seat showing our new design.
FIG. 2 is a front view of a seat.
FIG. 3 is a rear view of a seat.
FIG. 4 is a left side view of a seat.
FIG. 5 is a right side view of a seat.
FIG. 6 is a top view of a seat.
FIG. 7 is a bottom view of a seat; and,
FIG. 8 is an exploded view of a seat, showing the front, top and right sides.
The broken lines shown in FIG. 7 represent portions of the seat that form no part of the claimed design. The broken lines shown in FIG. 8 indicate the positional relationship between the exploded portion of the seat and the remainder of the seat, and form no part of the claimed design.