The ornamental design for a toolholster, as shown and described.
FIG. 1 is a front perspective view of a tool holster of the claimed design;
FIG. 2 is a rear perspective view of the tool holster of FIG. 1;
FIG. 3 is a front elevation view of the tool holster of FIG. 1;
FIG. 4 is a rear elevation view of the tool holster of FIG. 1;
FIG. 5 is a right elevation view of the tool holster of FIG. 1;
FIG. 6 is a left elevation view of the tool holster of FIG. 1;
FIG. 7 is a top plan view of the tool holster of FIG. 1; and,
FIG. 8 is a bottom plan view of the tool holster of FIG. 1.
The broken lines in the figures are for the purposes of illustrating portions of the tool holster or environmental structure and form no part of the claimed design.