fix: update doctests to use smol feature

[sinui0]

This PR updates the doctests on select and join functions to get rid of the deprecated with-smol-1 feature gate and uses the new smol feature instead.

Closes #214

Should smol be added into [dev-dependencies] so this sort of thing isn't possible? Doctests should ideally run fully without having to enable a feature.

[sinui0]

FYI, I searched and these are the only locations that contain these stale feature gates.

[thomaseizinger]

Should smol be added into [dev-dependencies] so this sort of thing isn't possible? Doctests should ideally run fully without having to enable a feature.

We can't do that because we are exposing helper functions here:

xtra/xtra/src/spawn.rs

Lines 31 to 44 in e96ae54

	/// Spawns the given actor into the smol runtime, returning an [`Address`](crate::Address) to it.
	#[cfg(feature = "smol")]
	#[cfg_attr(docsrs, doc(cfg(feature = "smol")))]
	pub fn spawn_smol<A>(
	actor: A,
	(address, mailbox): (crate::Address<A>, crate::Mailbox<A>),
	) -> crate::Address<A>
	where
	A: crate::Actor<Stop = ()>,
	{
	smol::spawn(crate::run(mailbox, actor)).detach();
	address
	}

.

[thomaseizinger]

Can you update to latest master? That should fix CI I believe!

[Restioson]

Happy to merge after passes CI

[sinui0]

All clear