fix(sdk): update SDK to support multiple withdrawal proofs (#9951)

.changeset/slimy-ducks-promise.md

+---
+'@eth-optimism/sdk': minor
+---
+
+Updates SDK for FPAC proven withdrawals mapping.

packages/sdk/src/interfaces/types.ts

@@ -258,14 +258,28 @@ export interface MessageReceipt {
 }
 
 /**
- * ProvenWithdrawal in OptimismPortal
+ * ProvenWithdrawal in OptimismPortal.
  */
-export interface ProvenWithdrawal {
+export interface LegacyProvenWithdrawal {
   outputRoot: string
   timestamp: BigNumber
   l2BlockNumber: BigNumber
 }
 
+/**
+ * ProvenWithdrawal in OptimismPortal (FPAC).
+ */
+export interface FPACProvenWithdrawal {
+  proofSubmitter: string
+  disputeGameProxy: string
+  timestamp: BigNumber
+}
+
+/**
+ * ProvenWithdrawal in OptimismPortal (FPAC or Legacy).
+ */
+export type ProvenWithdrawal = LegacyProvenWithdrawal | FPACProvenWithdrawal
+
 /**
  * Header for a state root batch.
  */