Anthony Marshall has wisely decided against asking a probate judge to support the sketchy third codicil to the will of his mother, Brooke Astor. The late addition, made after the ailing matriarch was over 100 years old, would have transferred $40 million of her real-estate holdings into cash to be managed by Marshall. This would have meant more fees for him and his lawyer, Francis Morrissey Jr. But a handwriting expert said last year that Brooke’s signature on the codicil had been forged — and a source told the Post that the issue was being dropped to avoid more scrutiny toward Marshall and his lawyer’s legal high jinks before Astor’s death. This is a good move for everyone involved, especially us, because it gives us something to write about on a Friday in late August.