The ornamental design for a wireless charging pencase, as shown and described.
FIG. 1 is a front, left side perspective view of a wireless charging pen case, showing my new design closed and in a first configuration;
FIG. 2 is a front, left side perspective view of the wireless charging pen case of FIG. 1, shown in a second configuration and exploded for clarity of disclosure;
FIG. 3 is a front view of the wireless charging pen case of FIG. 1, shown in the first configuration;