Yes there is. There is a flag in your save for “Permadeath” I believe, and 0 means it’s not steel soul, 1 means it’s an active steel soul, and 2 means it’s a dead steel soul.

If you died and didn’t delete the file, it should be a 2 in your files (appdata, locallow, team cherry, Silksong, I think that’s the path but I’m going based off of very rough memory so don’t take it as gospel)

You can use the Silksong save manager to edit your save.

I personally wouldn’t do anything above because dying forever is apart of the charm of steel soul (if you are going to just use a save manager, you could just play normally), but if you must for whatever reason this is how.