Week 8 of the 2021 NFL season begins Thursday with the Green Bay Packers visiting the undefeated Arizona Cardinals in Glendale, Ariz. The Los Angeles Times’ NFL writer, Sam Farmer, examines this week’s matchups. — Farmer’s record last week: 9-4 (.692); season — Farmer’s record last week: 9-4 (.692); season 70-37 (.654). Using point spreads with the scores Farmer predicted, the record against the…