The ornamental design for a toolholder, as shown and described.
FIG. 1 is a first perspective view of a tool holder showing my new design;
FIG. 2 is a second perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a back view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top view thereof;
FIG. 8 is a bottom view thereof; and,
FIG. 9 is an enlarged detail view of the encircled portion of FIG. 7.
The broken lines shown in the drawings depict portions of the tool holder in which the design is embodied that form no part of the claimed design. The dot-dash broken lines encircling the enlarged detail views are for the annotative purposes that form no part of the claimed design.