The ornamental design for a luminaire, as shown and described.
FIG. 1 is a front perspective view of a luminaire showing our new design;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a front end elevational view thereof;
FIG. 4 is a right side elevational view thereof, the left side being a mirror image;
FIG. 5 is a rear end elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The large broken line rectangles shown in FIGS. 1 and 3 represent Organic Light Emitting Diode (OLED) panels in the front of the luminaire; the small broken line circles at the top of the luminaire shown in FIGS. 1 and 7 represent openings for small LED lights; and the broken line structure at the bottom of the luminaire shown in FIGS. 1-7 represent a base plate for supporting the luminaire on a surface. The broken line structures form no part of our claimed design.