The ornamental design for a gardeningtool, as shown and described.
FIG. 1 is a top perspective view of my design comprising a gardening tool;
FIG. 2 is a left side view of my gardening tool, with the right side view being a mirror image of the left side view;
FIG. 3 is a front view of my gardening tool;
FIG. 4 is a back view of my gardening tool;
FIG. 5 is a bottom view of my gardening tool; and,
FIG. 6 is a top view of my gardening tool.
All other surfaces or portions of my gardening tool not shown in the figures or otherwise described in the specification form no part of the claimed design.