fix: etherscan per-sec rate limit no longer aborts cycle

[Flotapponnier]

Summary

• Remove chain 59144 (Linea) from etherscanMainnets — Etherscan free tier returns a per-second rate limit on every probe, triggering quotaHit=true which silenced the entire cycle
• Add max calls per sec check before the generic rate limit check in parseEtherscanBlockNoByTime — treats it as false, nil (skip chain, don't abort)
• Account-level quota (HTTP 402/429) is still handled via isQuotaStatus() on the HTTP layer

Root cause

{"status":"0","message":"Max calls per sec rate limit reached (3/sec)","result":""} from Linea matched strings.Contains(lr, "rate limit") → returned error → set quotaHit = true → published -1 for all fields for 36h+.