Convert pending block to a watch channel

[mattsse]

it is beneficial to have a listener for the pending block:

reth/crates/chain-state/src/in_memory.rs

Lines 50 to 51 in 7486d5b

	/// The pending block that has not yet been made canonical.
	pending: RwLock<Option<BlockState>>,

like we do with the latest as well:

reth/crates/chain-state/src/chain_info.rs

Lines 141 to 144 in 7486d5b

	/// The block that the beacon node considers safe.
	safe_block: watch::Sender<Option<SealedHeader>>,
	/// The block that the beacon node considers finalized.
	finalized_block: watch::Sender<Option<SealedHeader>>,

TODO

• convert RwLock into a watch channel

This will be useful for #5617

[mvares]

👊🏻

[mattsse]

hey @mvares this one's already taken by @jenpaff

perhaps I can interest you in #7490

[jenpaff]

Not related to this issue, but since it's my one, wanted to raise some questions for my own understanding:

• Small nit pick, but I noticed you don't have a rust-toolchain.toml and was wondering is there a reason? @mattsse
• 2 tests in lockfile.rs are still failing locally for me on main, will debug, I suppose that's on my end

[mattsse]

but I noticed you don't have a rust-toolchain.toml and was wondering is there a reason

can't remember why, likely because we never needed it

2 tests in lockfile.rs are still failing locally for me on main, will debug, I suppose that's on my end

It could be because there are some issues if they are run in the same process via cargo t in CI this isn't an issue with cargo nextest