Coroutines panic when trying to unwrap manual_time

[vdrn]

https://github.com/not-fl3/macroquad/blob/81ca7b41087315017864135be0bb734b840f270a/src/experimental/coroutines.rs#L188

It happens when I have multiple nodes of the same type that uses StateMachine and Coroutines. Those coroutines are not necessarily executing when the panic happens. Also, none of those coroutines use manual polling.

Note: adding a is_some guard for that line solves the issue for me with no noticeable consequences.