Storage issue with not installed os update

I tried downloading macOs Sonoma on my macbook air, which showed up as around 15gb of space, and so I proceeded with the download but when I tried installing it to my built in hard drive it said that I don't have enough storage to do so because I suppose that I had a few past updates that I haven't installed, so I would need much more space to actually install the update. And so I did not install it because I couldn't, and I deleted the installer, but the storage space of the Sonoma update still got eaten and now I'm down 15gb of storage space without any way of deleting it, even though I haven't actually installed the update. Please help me recover this storage.