Remove ! from todo!() in comments (#8643)

This practice makes it difficult to locate todo!s in my code when I'm
working. Let's take out the bang if we want to keep doing this.

Release Notes:

- N/A

crates/fs/src/fs.rs

@@ -1343,7 +1343,7 @@ pub fn copy_recursive<'a>(
     .boxed()
 }
 
-// todo!(windows)
+// todo(windows)
 // can we get file id not open the file twice?
 // https://github.com/rust-lang/rust/issues/63010
 #[cfg(target_os = "windows")]