The ornamental design for a spout, as shown and described.
FIG. 1 is a front perspective view of a spout showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a top view thereof; and,
FIG. 6 is a bottom view thereof.
The uneven length broken line immediately adjacent to the photographic region represents an unclaimed boundary of the design. The even broken line showing of the remainder of the spout is for environmental purposes only and forms no part of the claimed design.