you could try cleaning the fans and heat-sink, fans can make more noise if they go off balance because of dust buildup etc...
If that doesn't work and your sure the noise is from the GPU, I'm pretty sure nitro+ cards have a thing called quick connect fans, IDK if that's on your card or not? but I remember seeing a you-tube vid where a guy was doing a review and had an RGB fan upgrade kit for a nitro+ card, that could mean replacement fans for that card might exist
It probably isn't doing any harm tho, so long as your temps are still fine it's just an annoying noise, if it bothers you try to fix it, if not don't worry unless it gets really bad