The ornamental design for a petbowl, as shown and described.
FIG. 1 is a front isometric view of the pet bowl of the present invention;
FIG. 2 is front view thereof, the rear view being a mirror image thereof;
FIG. 3 is a left-side view, the right-side view being a mirror image thereof; and,
FIG. 4 is a top plan view thereof.
The broken lines shown in the interior illustrate portions of the pet bowl that form no part of the claimed design. The dot-dashed broken lines represent the bounds of the claim and form no part of the claimed design.