Show some respect!
Boromir is a hero. If the bar for not being a hero is that one was not tempted by the ring then there are no heroes in LOTR

Galadriel, Gandalf, Bombadil, or Faramir?

I guess it depends on your definition of “tempted”. All four of these characters had the opportunity to take the ring, but ultimately did not.

Galadriel was certainly tempted by it—in fact, I’m sure she fully intended to take it from Frodo.

Gandalf had clearly considered using it at some stage, but rejected the idea.

Tom Bombadil wasn’t capable of being tempted by it. It seems the only thing that could tempt him was Goldberry.

And Faramir doesn’t seem to have been affected by it at all and rejected the idea of using it out of hand, even before knowing exactly what it was.