Definitely not. Spawn belongs to Image Comics. DC Comics has nothing to do with Spawn. They have their own roster of heroes and villains that are different from those in the Spawn universe.
Spawn doesn't belong to Marvel or DC. It's an independent creation by Todd McFarlane and is part of the Image Comics universe. Image Comics gives Spawn its own unique storyline and world.
Spawn comics have indeed come to an end. The decision to end it might have been based on various factors such as creative direction, sales figures, or the story reaching a natural conclusion.