swap: exclude non-active swap in csvPassedCallback

csv wait list is always added in AwaitPaymentOrCsvAction state
 but removed only after csvPassedCallback.

csvPassedCallback always assumes an active swap, but in normal flows
like preimage path, the swap might be complete,
leaving no active swap at this point.
This was not considered before, causing continuous errors.

swap/service.go

@@ -348,6 +348,9 @@ func (s *SwapService) OnTxConfirmed(swapId string, txHex string, gotErr error) e
 // OnCsvPassed sends the csvpassed event to the corresponding swap
 func (s *SwapService) OnCsvPassed(swapId string) error {
 	swap, err := s.GetActiveSwap(swapId)
+	if errors.Is(err, ErrSwapDoesNotExist) {
+		return nil
+	}
 	if err != nil {
 		return err
 	}