If the Federal Trade Commission clears grocery giant Albertsons’ $20 billion sale to Kroger on schedule next month, the private-equity investors who control this collection of U.S. grocery and drug store chains will have squeezed out profits nine times larger than what they invested since 2006. That’s about triple what you and I and our retirement plans (if any) would have gotten if we put our money in the S&P 500 stock index over the same period. And it’s a lot more than grocery workers’ wages have risen, even with pandemic-era gains caused by labor shortages and hiring competition from Amazo…