Whenever there is a payment failure that requires gossip update, for
example changing the fee rates of remote channels, we call addgossip.
For renepay to consider this changes in the coming payment attempts, it
must update gossmap.
Any file in this directory which is executable and whose name only
consists of alphanumeric characters, space, '.', '-' or '_' will be
automatically loaded when lightningd starts (unless suppressed with
commandline options).
c916066f85