Do not break slate linkintegrity if block is not a slate block

src/plone/restapi/blocks_linkintegrity.py

@@ -69,9 +69,8 @@ def __init__(self, context, request):
     def __call__(self, block):
         value = (block or {}).get(self.field, [])
         children = iterate_children(value or [])
-
         for child in children:
-            node_type = child.get("type")
+            node_type = child.get("type", "")
             if node_type:
                 handler = getattr(self, f"handle_{node_type}", None)
                 if handler:

src/plone/restapi/deserializer/blocks.py

@@ -24,9 +24,10 @@ def iterate_children(value):
     queue = deque(value)
     while queue:
         child = queue.pop()
-        yield child
-        if child.get("children"):
-            queue.extend(child["children"] or [])
+        if isinstance(child, dict):
+            yield child
+            if child.get("children", []):
+                queue.extend(child["children"] or [])
 
 
 @implementer(IFieldDeserializer)