The ornamental design for a dustpan, as shown and described.
FIG. 1 is a front perspective view of a dustpan showing our new design positioned in a first configuration;
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 the top plan view thereof;
FIG. 7 is the bottom plan view thereof;
FIG. 8 is a front perspective view of the dustpan positioned in a second configuration;
FIG. 9 is a rear perspective view of the dustpan in the first configuration; and,
FIG. 10 is a rear perspective view of the dustpan in the second configuration.
The broken lines in the drawings depict portions of the dustpan that form no part of the claimed design. In particular, the dustpan bail, the dustpan handle, including the shaft and circular end, and also the associated broom head and broom handle form no part of the claimed design.