I claim the ornamental design for the hitch assembly, as shown and described.
FIG. 1 is a perspective view of a hitch assembly showing my new design;
FIG. 2 is a top plan view thereof; the opposite side being a mirror image,
FIG. 3 is a left side elevation view thereof;
FIG. 4 is a right side elevation view thereof; and,
FIG. 5 is a front elevation view thereof; with the shackle portion of the hitch assembly in a pivoted configuration and the opposite side being a mirror image.