Once an artifact/release binary has been uploaded/attached to a tag (ex: v0.7), you cannot upload another file with the same name even if using a different tag (ex: v0.8).
Use case: The resulting binary of my project is called "whatever.exe" and I would like to be able to use the same name for the different releases I make (instead of having to use "whatever_0.1.exe", "whatever_0.2.exe", etc...)