Merge branch 'feature/AbsorbTransposeIntoMT_only_linear' into feature/AbsorbConsecutiveTransposes

src/finn/transformation/streamline/absorb.py

@@ -317,11 +317,13 @@ class AbsorbTransposeIntoMultiThreshold(Transformation):
         graph_modified = False
         for n in graph.node:
             node_ind += 1
-            if n.op_type == "Transpose":
+            if n.op_type == "Transpose" and not model.is_fork_node(n):
                 perms = list(get_by_name(n.attribute, "perm").ints)
                 if perms == [0, 3, 1, 2]:
                     mt_cand = model.find_consumer(n.output[0])
-                    if mt_cand.op_type == "MultiThreshold":
+                    if mt_cand.op_type == "MultiThreshold" and not model.is_fork_node(
+                        mt_cand
+                    ):
                         final_t_cand = model.find_consumer(mt_cand.output[0])
                         if final_t_cand.op_type == "Transpose":
                             perms = list(