grossly excessive peer discovery

[just-mitch]

I ran with 48 validators and looked at the aztec:libp2p_service logs enabled on the boot node. I'm seeing:

Already connected to peer 16Uiu2HAkxo...
Handling discovered peer 16Uiu2HAkxo...

Multiple times per second. That is, I'm seeing that we discover and handle the same peer multiple times per second.

Hypothesis is that if we reduce the max peer count, this will go away: we're trying to discover until we max out.

[Maddiaa0]

Is this still an issue, i would imagine this is greatly reduced by #10891