In his State of the City speech in January, Mayor Bill de Blasio promised that the city would create a system of retirement security for millions of New Yorkers who work in the private sector and may not have access to employer-provided savings plans. It was a revival of an effort the mayor had first pushed in 2016 but that bumped up against the change in presidential administrations and federal approvals apparently needed. But eight months after de Blasio’s speech at the start of this year, the New York City Council is ready to look at the idea through two bills that will be examined at a hearing later this month.