On a recent afternoon in the gardens of the Palace of Versailles, outside Paris, a 17th-century statue of Apollo became chatty. He answered questions about his past and praised the garden’s caretakers for quickly dealing with any errant bird droppings. The statue “spoke” through an app, powered by artificial intelligence, that lets visitors converse with 20 outdoor statues in three languages. The new tool is part of an effort by the palace to lure younger and more homegrown audiences.