A cold-blooded Brooklyn man was found guilty of fatally shooting his ex-girlfriend point-blank in the head as she pushed their three-month-old baby girl in a stroller .  Isaac Argro was convicted of murder in Manhattan court on Thursday – four years after he put a bullet through Azsia Johnson’s temple during the Upper East Side attack on June 29 2022.  After a weeks-long trial, the jury found Argo, 26, guilty of the heinous crime within two hours of deliberation. Isaac Argro, seen in court Thursday, was found guilty after a weeks-long trial. Steven Hirsch for NY Post Azsia Johnson, was shot dead while walking with her three-month-old baby in 2022. Nefertari Jay / Facebook “This brutal execution devastated all of Ms.…