The ornamental design for an awning, as shown and described.
FIG. 1 is a front, right perspective view of an awning in accordance with the present invention;
FIG. 2 is a right side, elevation view thereof;
FIG. 3 is a front, elevation view thereof;
FIG. 4 is a top, elevation view thereof;
FIG. 5 is a left side, elevation view thereof; and,
FIG. 6 is a rear, elevation view thereof.
The broken lines showing a possible portable shelter to which the awning of the present invention is attached is for illustrative purposes only and forms no part of the claimed design.