The Hard Rock casino reached agreement with Atlantic City’s main casino workers union on Saturday, removing the last threat of a strike during the busy holiday weekend and clearing the way for the gambling halls and their workers to concentrate on bouncing back from financial losses during the coronavirus pandemic. Local 54 of the Unite Here union said it reached a tentative agreement with Hard Rock, avoiding a strike that had been threatened for 12:01 a.m. Sunday. Combined with agreements reached Thursday with the Borgata, Caesars, Harrah’s and the Tropicana, Hard Rock’s deal leaves only two …