Gas Can Vent Cap

FIG. 1 is a front, top, and left perspective view of a gas can vent cap showing my new design; FIG. 2 is a front elevational view thereof; FIG. 3 is a rear elevational view thereof; FIG. 4 is a left side elevational view thereof; FIG. 5 is a right 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 rear, bottom, and right perspective view thereof. The broken lines shown in the drawings represent portions of the gas can vent cap that form no part of the claimed design.