lookahead collator: read allowed ancestry len from relay client

[slumber]

Implements 2nd approach from paritytech/cumulus#2706 (comment)

[rphmeier]

Does what it's supposed to.

Even better would be to extract out a fn load_abridged_host_configuration to cumulus/client/consensus/common.

[slumber]

Does what it's supposed to.

Even better would be to extract out a fn load_abridged_host_configuration to cumulus/client/consensus/common.

I thought about making it a part of relay client, but e.g.

polkadot-sdk/cumulus/primitives/parachain-inherent/src/client_side.rs

Lines 38 to 52 in 2c17d39

	let ingress_channels = relay_chain_interface
	.get_storage_by_key(
	relay_parent,
	&relay_well_known_keys::hrmp_ingress_channel_index(para_id),
	)
	.await
	.map_err(|e| {
	tracing::error!(
	target: LOG_TARGET,
	relay_parent = ?relay_parent,
	error = ?e,
	"Cannot obtain the hrmp ingress channel."
	)
	})
	.ok()?;

Just uses get_storage_by_key explicitly with localized log target.

[slumber]

bot merge

[command-bot]

@slumber Unknown command "merge". Refer to help docs and/or source code.