Darden Restaurants was hit hard by the omicron variant of the coronavirus pandemic in January, with more than 13,000 employees missing work that month, company leaders revealed Thursday. The owner of Olive Garden and other chain restaurants in January saw employees unable to work at a level three times greater than the monthly peak it experienced during the earlier delta variant, said chief operating officer Rick Cardenas. Darden has about 175,000 employees. Some restaurants were down as much as 40% of their staff and others needed to limit hours or only offer takeout temporarily, Cardenas sai…