The ornamental design for a shirt, as shown and described.
FIG. 1 is a front view of a shirt according to the design;
FIG. 2 is a rear view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a front perspective view thereof;
FIG. 6 is a right side rear perspective view thereof;
FIG. 7 is a left side rear perspective view thereof with an upper panel thereof shown in a closed position;
FIG. 8 is a left side rear perspective view thereof with the upper panel thereof shown in an opened position; and,
FIG. 9 is a rear view thereof shown in an environment of use.
The portions of the shirt shown in dashed broken lines in FIGS. 1-9 do not form part of the claimed design. The dashed broken line showing of the hands, legs, torso, neck, and head in FIG. 9 is for the purpose of illustrating portions of the environmental structure and forms no part of the claimed design. The dot-dash broken lines shown in FIGS. 3-4 are for illustrating the boundary of the design only and do not form part of the claimed design. The upper panel on the rear of the shirt is not attached to the lower panel along the outer edge of the upper panel as shown in FIG. 8.