If folks at GitHub believe they offer a product of value (which I suspect that they do), then the necessary corollary is that by offering that product to an agency responsible for a reprehensible abrogation of human rights makes it easier, cheaper, and/or faster for that agency to degrade humanity. To stick one's fingers in one's ears and claim that it is "apolitical" to continue to do business with such an agency is embarrassingly similar to the defenses that IBM executives must have made in the 1930's.
1/3 of my people were subject to genocide infamously by oven, more recently than slavery, but I'm not expecting people to remove any reference to fire or pizza from my life, that would be absurd. So is this. None of the people coding were slaves, I guarantee it, and they can move past it just like all other populations move past various atrocities that they experience. This focus on blacks is a fad, you can arbitrarily define a near infinite number of "marginalized" groups if you carve up 360MM people.
But what does make it difficult is being told all your life that you are a victim, held back by something about yourself that you cannot change; that's how you breed weakness and teach learned helplessness.
Treating other humans with respect is a core value of mine. I try as much as I can to listen to their concerns and be mindful of them. I'm truly sorry that you seem to only see this long-awaited reckoning with America's deep white supremacist roots as a "fad".