fix: funding script for sealevel (#8553)

Author: troykessler

.changeset/five-doors-fold.md

@@ -0,0 +1,5 @@
+---
+"@hyperlane-xyz/sdk": patch
+---
+
+Fixed sealevel fee payer

typescript/sdk/src/signers/svm/solana-web3js.ts

@@ -167,6 +167,10 @@ export class SvmMultiProtocolSignerAdapter implements IMultiProtocolSigner<Proto
 
     transaction.recentBlockhash = blockhash;
 
+    if (!transaction.feePayer) {
+      transaction.feePayer = this.signer.publicKey;
+    }
+
     // Sign with extra signers first (e.g., randomWallet for Sealevel transferRemote).
     // Uses partialSign to avoid clearing any existing signatures.
     // This re-signs with the fresh blockhash, overwriting the adapter's pre-sign.