We claim the ornamental design for a carabiner, as shown.
FIG. 1 is a perspective view of a carabiner according to an embodiment of the invention.
FIG. 2 is a right side view of the carabiner of FIG. 1.
FIG. 3 is a left side view of the carabiner of FIG. 1.
FIG. 4 is a back side view of the carabiner of FIG. 1.
FIG. 5 is a front side view of the carabiner of FIG. 1.
FIG. 6 is a top side view of the carabiner of FIG. 1; and,
FIG. 7 is a bottom side view of the carabiner of FIG. 1.
The elements shown in broken lines form no part of the claimed design and are included for the purpose of showing the environment of the claimed design. Any broken lines having unequal line segments indicate the boundary of the claimed design.