New York’s woke mental health system — which refuses to lock up even violent maniacs — is as much to blame for the unprovoked fatal shoving of a retired teacher as the suspect himself, critics told The Post. “It was the quintessential preventable tragedy,” Carolyn D. Gorman, a fellow at the Manhattan Institute, said Saturday. “I think there are two issues: There’s a lack of [patient] beds, and there’s a lack of willingness to hold individuals, whether in a locked psychiatric facility … or in a