I claim the ornamental design for a skirt, as shown and described.
FIG. 1 is a rear perspective view of the first embodiment of a skirt showing my new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a right side elevation view thereof;
FIG. 5 is a left-side elevation view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof;
FIG. 8 is a rear perspective view of a second embodiment thereof;
FIG. 9 is a front elevation view thereof;
FIG. 10 is a rear elevation view thereof; and,
FIG. 11 is a top plan view thereof.
The dash-dash broken lines shown in the figures depict stitching and form part of the claimed design. The dot-dash broken lines shown in the figures illustrate environmental subject matter and do not themselves form a part of the claimed design.