Send idontwant on publish

[pawanjay176]

Issue Addressed

N/A

Proposed Changes

Send an idontwant after publishing on any topic. Normally, we would only expect idontwants to be useful for fanouts but I don't expect to see any significant improvement after merging https://github.com/sigp/lighthouse/pull/8269 .

But regardless, I feel like sending idontwants on publish is the sensible default. I don't want to merge this until fulu is activated on mainnet and we can test it on a mainnet like network. I feel that testing this on devnets wouldn't be very representative.