Doesn't really matter mate, just be consistent in counting or not counting it so you can reliably track progress.
The bar is included in the weight you lift but since it's the same bar every time it's a constant; the variable being the load added, and it's the exercise variables we're interested in (linear increases please
).
You could count the bar as 500lbs if you wanted, as long as you count it 500lbs every time you're fine.