[c-lightning] Core Lightning v24.08 - Steel Backed-up Channels

[Shahana Farooqui]

Hello Everyone,

We are pleased to announce the 24.08 release of Core Lightning, named by
@Lagrang3. For a list of all changes, please see the changelog.

*Highlights for Users*

   - `pay` now checks for sufficient spendable capacity before computing a
   route and returns a clear error message if there isn't enough capacity.
   - `offers` can now self-fetch and self-pay BOLT12 offers and invoices.
   - `offers` automatically adds a blinded path from a peer if we have no
   public channels, and supports setting a blinded path for `invoicerequest`
   if we're an unannounced node.
   - `renepay` now prunes the network by disabling undesired channels,
   un-reserves routes after use, and introduces a new `exclude` option for
   channels & nodes to be excluded from routing.
   - Whitespace at the end of (most) options will not complain anymore.
   - I/O optimizations to significantly speed up larger nodes.


*Highlights for the Network*

   - `pay` can now pay to bolt12 invoices if entry to blinded hop is
   specified as a `short_channel_id`.
   - We can now open unannounced channels with LND nodes again.
   - Onion messages are now supported by default and can be forwarded using
   `short_channel_id`.
   - We now request all gossip from the first peer and immediately send
   updated gossip to current peers instead of waiting for reconnections.
   - Recurring offers had incompatible changes, it will not work against
   older versions.


*Highlights for Developers*

   - New experimental plugin `askrene` accesses min-cost-flow route
   calculations.
   - `pay` plugin now includes enhanced logging and improved error codes,
   and emits `channel_hint_updated` notifications to share inferred balances
   across payments.
   - New `reckless-rpc` plugin allows users to issue commands to reckless
   over rpc.
   - Plugin manager `reckless` now supports installing Rust plugins,
   accepts JSON array input and provides JSON output with the `-j/--json`
   option flag.
   - `bookkeeper` now listens for two new custom events: `utxo_deposit` and
   `utxo_spend`.


Since 24.05, we've had 375 commits by 21 authors in 84 days!

A special thanks to the eight first time contributors:

   - michael1011
   - Epic Curious
   - Tommy Volk
   - Pavol Rusnak
   - Max Rantil
   - Jose Storopoli
   - Joseph Goulden
   - jackstar12


Thanks,
Shahana.