fix(proposer): SplitRangeBasedOnSafeHeads fallback

[ratankaliani]

It is possible for the safeDB to exist, but optimism_safeHeadAtL1Block fails on a specific block because the safeDb is not fully synced.

In this case, add a fallback to the safe db range-splitting algorithm to use the basic range splitting algorithm in the event of an error.

[github-actions]

Metric	Value
Batch Start	21,120,930
Batch End	21,120,935
Witness Generation (seconds)	83
Execution Duration (seconds)	41
Total Instruction Count	1,313,868,556
Oracle Verify Cycles	342,083,464
Derivation Cycles	608,733,584
Block Execution Cycles	247,157,699
Blob Verification Cycles	151,850,377
Total SP1 Gas	1,547,661,339
Number of Blocks	6
Number of Transactions	50
Ethereum Gas Used	18,569,579
Cycles per Block	218,978,092
Cycles per Transaction	26,277,371
Transactions per Block	8
Gas Used per Block	3,094,929
Gas Used per Transaction	371,391
BN Pair Cycles	0
BN Add Cycles	0
BN Mul Cycles	0
KZG Eval Cycles	0
EC Recover Cycles	270,551