Remove verbose warning log in l1-finalized fetcher

[ezdac]

The log warning in the finalized l1 ref fetcher seems overly verbose.
It logs every time the fetcher is called with a ref higher than the current local l1-finalized head.

optimism/op-node/rollup/finalized/finalized.go

Line 28 in d3383ca

f.log.Warn("requested L1 block is beyond local finalized height", "requested_block", num, "finalized_block", l1Finalized.Number)

The fetcher is mostly used in a try-backoff-retry way and this appears constantly in normal operation on the sequencer.

I think we should remove this log message, or at least change this to debug level.