I claim the ornamental design for a produce bin, as shown and described.
FIG. 1 is a prespective view of a produce bin according to the design, the containers for bin being shown in phantom and forming no part of the design;
FIG. 2 is a planar front view of the produce bin;
FIG. 3 is a planar rear view of the produce bin, the fluid conduits for the bin being shown in phantom here, and in FIGS. 4-7, and forming no part of the design;
FIG. 4 is a planar top view of the produce bin;
FIG. 5 is a view of one side of the produce bin;
FIG. 6 is a view of the opposite side of the produce bin; and,