`cashu-sdk/mint` fix: `process_split_request` add secrets to spent after they are verified

crates/cashu-sdk/src/mint.rs

@@ -148,14 +148,14 @@ impl Mint {
             return Err(Error::DuplicateProofs);
         }
 
-        for secret in secrets {
-            self.spent_secrets.insert(secret);
-        }
-
         for proof in &split_request.proofs {
             self.verify_proof(proof)?
         }
 
+        for secret in secrets {
+            self.spent_secrets.insert(secret);
+        }
+
         match &split_request.amount {
             None => {
                 let promises: Vec<BlindedSignature> = split_request