The obligation to ensure traffic safety on streets and sidewalks lies primarily with cities and municipalities. They must ensure that citizens can get from A to B safely. However, this obligation can be transferred to owners by law. These, in turn, can pass it on to tenants via a clause in the rental agreement.
It is therefore important to clarify the situation first: Does the municipality perhaps also take over the cleaning of the sidewalks, is there a concierge service that removes the leaves or perhaps even has to you do it yourself? If there is nothing about this in the rental agreement, you as the tenant are out of the loop for now.
There, the city supports the removal of the leaves. Outside this area, owners are required to “clean the sidewalk, parking areas, cycle paths and the road, including the ravine, to the middle of the lane”.