I claim the ornamental design for an item holder for seat, as shown and described.
FIG. 1 is a perspective view of an item holder for seat, showing my new design with a pouch thereof in a closed position;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right-side elevational view thereof;
FIG. 5 is a left-side elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a perspective view thereof, illustrated with the pouch in an open position.
The broken lines showing a seat and a retained item in FIG. 1 depict environmental matter and form no part of the claimed design. The remaining broken lines represent stitching, and are part of the claimed design.