This Sunday, June 21, is the Summer Solstice in the Northern Hemisphere, which officially marks the first day of summer. To celebrate the arrival of many people’s favorite time of the year, the supermarket giant Kroger is giving away 100,000 free pints of ice cream. But if you want one, you’ll have to act fast today. How do I get my free ice cream from Kroger? Kroger and its subsidiaries are giving away 100,000 pints of ice cream through a coupo…