The lone holdout Manhattan juror in the 2015 Etan Patz murder trial is blasting Monday’s US Supreme Court decision to restore the conviction of Pedro Hernandez. The former juror told The Post he remains convinced that the state’s case against Hernandez was built on “a house of cards” and that the real killer is still out there — decades after the 6-year-old boy’s tragic disappearance from a SoHo street in 1979. “I’m just sad for the [supreme court] outcome and sad for what it means for Pedro’s