I can think of plenty of great novels that don't feature a romance or a love interest.
In some of them, the "love story" is platonic love instead of romantic. Off the top of my head, Blackwing by Ed McDonald has a big romantic arc, but it also has an arc with the main character's oldest friend. She's mortally injured in one of the early battles, and the MC makes awful deals and sells part of his soul to save her, only to have her open up to him later about how she's never really felt like his equal. After everything he did for her, they end the book on uneven footing. It's one of my favorite friend-relationship arcs I've read recently. It's messy, like an actual friendship.
I think if you're concerned about not having a romance arc, have a full and complicated friendship arc instead. Explore why these characters are friends and how their friendship changes over the course of the book as the characters grow. Have them save each other, rely on each other, and at times disappoint each other.
Short answer: no, you don't need one. Longer answer: Make your friendship arc as full and dynamic as a good romance arc.