optimize transaction filter

src/main/java/com/faf223/expensetrackerfaf/util/TransactionFilter.java

@@ -17,14 +17,13 @@ public class TransactionFilter {
     private final CredentialService credentialService;
 
     public List<? extends IMoneyTransaction> filterByEmail(List<? extends IMoneyTransaction> transactions, String email) {
-        return transactions
-                .stream()
-                .filter(transaction -> {
         Optional<Credential> credential = credentialService.findByEmail(email);
         if(credential.isEmpty())
             throw new UserNotFoundException("The user has not been found");
-                    return credential.get().getUser().equals(transaction.getUser());
-                })
+
+        return transactions
+                .stream()
+                .filter(transaction -> credential.get().getUser().equals(transaction.getUser()))
                 .toList();
     }