The ornamental design for a collapsibleenclosure, as shown and described.
FIG. 1 is a perspective view of collapsible enclosure showing my new design;
FIG. 2 is a front elevational view of the collapsible enclosure of FIG. 1;
FIG. 3 is a right side elevational view of the collapsible enclosure of FIG. 1;
FIG. 4 is a rear elevational view of the collapsible enclosure of FIG. 1, the opposite side being a mirror image thereof;
FIG. 5 is a left side elevational view of the collapsible enclosure of FIG. 1; and,
FIG. 6 is a top plan view of the collapsible enclosure of FIG. 1.
The broken lines showing a pair of zippers in FIGS. 1 and 3 and a skirt around a base of the collapsible enclosure in FIGS. 1 and 6 are for illustrative purposes only and form no part of the claimed design.