x/lightclient redundent call for FindStateInfoByHeight

[mtsitrin]

// Check for the last BD from the previous stateInfo as now we have the nextValhash available for that block
blockValHash, found := hook.k.GetConsensusStateValHash(ctx, canonicalClient, stateInfo.StartHeight-1)
if found {
previousStateInfo, err := hook.k.rollappKeeper.FindStateInfoByHeight(ctx, rollappId, stateInfo.StartHeight-1)
if err != nil {
	return err
}

this code calls FindStateInfoByHeight while it can just get the previous state index.
FindStateInfoByHeight is inefficient for this use case

[danwt]

this is micro optimization unless you can show it's a bottleneck

[mtsitrin]

this is micro optimization unless you can show it's a bottleneck

why not taking the previous state index? why u need to "FindStateInfo" if it's index is known?