We claim the ornamental design for a drill bit, as shown and described.
FIG. 1 is a perspective view of a drill bit.
FIG. 2 is a first side view of the drill bit of FIG. 1.
FIG. 3 is a second side view of the drill bit of FIG. 1.
FIG. 4 is a third side view of the drill bit of FIG. 1.
FIG. 5 is a fourth side view of the drill bit of FIG. 1; and,
FIG. 6 is a first end view of the drill bit of FIG. 1.
Any portion of the drill bit shown in broken lines is included for the purpose of illustrating portions of the drill bit and forms no part of the claimed design. The drill bit is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.