Subscriptions not closing after done

[nedsalk]

Subscriptions that are not manually cancelled (e.g. with a break in a for-await-of loop) do not end when the underlying stream closes.
This is because the current implementation with the FuelSubscriptionStream stream transformer ignores the value which signifies stream completion {value: undefined, done: true}, as explained on the MDN:

If the stream becomes closed, the promise will be fulfilled with an object of the form { value: undefined, done: true }.

[arboleya]

Related:
https://forum.fuel.network/t/failed-to-deploy-contract-using-typescript-sdk/4440