rpc: delist dead keyless endpoints (nodies avax/gnosis, merkle base/bnb)

[Flotapponnier]

Verified from a clean residential IP 2026-07-09:

• nodies avalanche + gnosis: 403 "requires a paid subscription plan" -> free-tier premise gone, delisted (spec blocks + probe entries + editorial counts/mentions updated)
• merkle base + bnb: 200 OK from residential, 100% errors from our probes -> datacenter-IP lockout, same behavior that already excludes it on Ethereum; delisted under the documented cluster rule
• cloudflare ethereum: -32046 from any IP; KEPT as the page's documented cautionary tale (reliability column is the story), but excluded from RpcProviderErrorRate so it stops reminding twice a day

63 specs valid, harness builds.