The ornamental design for a lift harness, substantially as shown.
FIG. 1 is a perspective view of a lift harness showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a rear view thereof;
FIG. 6 is a right side view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines on the harness in FIGS. 1, 2 and 5 are for the purposes of illustrating portions of the lift harness and form no part of the claimed design. The broken lines of the human figure in FIG. 1 are for the purposes of illustrating environmental structure and form no part of the claimed design.