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fix bare except

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: marcomusy

vedo/assembly.py

@@ -137,7 +137,7 @@ def __iadd__(self, obj):
             if a:
                 try:
                     self.AddPart(a)
-                except:
+                except AttributeError:
                     self.AddPart(a.actor)
         return self