[v1 Maintenance] Back port MapExpansion fixes from v2 (#2257)

This PR brings the fixes to `MapExpansion` [transform done in
v2](https://github.com/spcl/dace/blob/156567b1eea3b54cd3dda0b6d3f259995127be68/dace/transformation/dataflow/map_expansion.py#L135)
back into v1.

Author: FlorianDeconinck

dace/transformation/dataflow/map_expansion.py

@@ -136,10 +136,14 @@ def apply(self, graph: dace.SDFGState, sdfg: dace.SDFG):
             graph.add_edge(entries[-1], edge.src_conn, edge.dst, edge.dst_conn, memlet=copy.deepcopy(edge.data))
             graph.remove_edge(edge)
 
-        if graph.in_degree(map_entry) == 0:
+        if graph.in_degree(map_entry) == 0 or all(
+                e.dst_conn is None or not e.dst_conn.startswith("IN_")
+                for e in graph.in_edges(map_entry)):
             graph.add_memlet_path(map_entry, *entries, memlet=dace.Memlet())
         else:
             for edge in graph.in_edges(map_entry):
+                if edge.dst_conn is None:
+                    continue
                 if not edge.dst_conn.startswith("IN_"):
                     continue