fix: skip first block in cost estimation for initial range

[fakedev9999]

When calculating execution statistics for cost estimation, skip the first block if it's the very first range in the sequence, as this block is not actually executed. This prevents including non-executed blocks in stats, especially for the number of blocks, leading to more accurate estimates.

[github-actions]

Metric	Value
Batch Start	22,631,130
Batch End	22,631,135
Witness Generation (seconds)	27
Execution Duration (seconds)	36
Total Instruction Count	1,748,427,932
Oracle Verify Cycles	251,814,279
Derivation Cycles	1,319,088,854
Block Execution Cycles	90,664,563
Blob Verification Cycles	106,759,119
Total SP1 Gas	0
Number of Blocks	6
Number of Transactions	42
Ethereum Gas Used	4,985,320
Cycles per Block	291,404,655
Cycles per Transaction	41,629,236
Transactions per Block	7
Gas Used per Block	830,886
Gas Used per Transaction	118,698
BN Pair Cycles	0
BN Add Cycles	0
BN Mul Cycles	0
KZG Eval Cycles	0
EC Recover Cycles	923,440
P256 Verify Cycles	0