Those approaching retirement can now buy a type of “insurance” to guard against reduced Social Security benefits. The product — a rider on an annuity — is the first of its kind, but some experts expect similar offerings to follow as worries over the future of the entitlement program grow due to the pandemic. “The largest unaddressed fear is the Social Security reduction,” said David Duley, founder and CEO of PlanGap, which has received regulatory approval for the new product in 44 states…