The ornamental design for a shoulder harness, as shown and described.
FIG. 1 is a front perspective view configured to be worn over a right shoulder.
FIG. 2 is a front perspective view configured to be worn over a right shoulder with a pocket strap and clip in an open position.
FIG. 3 is a rear perspective view configured to be worn over a right shoulder.
FIG. 4 is a front perspective view configured to be worn over a left shoulder.
FIG. 5 is a rear perspective view configured to be worn over a left shoulder.
FIG. 6 is a front in-use perspective view configured to be worn over a right shoulder; and,
FIG. 7 is a front in-use perspective view configured to be worn over a left shoulder.
The broken lines in the drawings depict portions of the shoulder harness that form no part of the claimed design. The broken lines in FIGS. 6 and 7 depicting a person holding a tool represent environmental subject matter that forms no part of the claimed design.