The ornamental design for a dolly for a cleaning apparatus, as shown and described.
FIG. 1 is a side perspective view of a dolly for a cleaning apparatus in accordance with the present design;
FIG. 2 is a right side view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a front view thereof;
FIG. 5 is a back view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines shown in the figures are included for the purpose of illustrating portions of the dolly for a cleaning apparatus and form no part of the claimed design.