Not Very Helpful
Some neighbors will go out of their way to help you while others will do the exact opposite. Whoever lives next door to this OP clearly belongs to the latter category. To be fair, the neighbor can’t technically be blamed for just cleaning their side of the stairs but seriously?
Would it have been that hard to go the extra mile? It wouldn’t have taken too much time or extra effort to just scoop away the snow from the other half of the staircase as well. It just seems extremely petty but maybe they have a solid reason that we don’t know about.