Draft: AthContainers: Don't copy decorations with an AuxElement.
When we copy an AuxElement, don't copy decorations. Another thread may be modifying them, which can lead to corruption/crashes. See ATLASRECTS-8008.
When we copy an AuxElement, don't copy decorations. Another thread may be modifying them, which can lead to corruption/crashes. See ATLASRECTS-8008.