tapdb: align unit tests with in-code comments

This commit updates the unit tests to accurately reflect and comply with
the intended behavior outlined in the in-code comments.

tapdb/assets_store_test.go

@@ -2090,7 +2090,9 @@ func TestTransferOutputProofDeliveryStatus(t *testing.T) {
 
 	// At this point, we should be able to query for the log parcel, by
 	// looking for all unconfirmed transfers.
-	assetTransfers, err := db.QueryAssetTransfers(ctx, TransferQuery{})
+	assetTransfers, err := db.QueryAssetTransfers(ctx, TransferQuery{
+		PendingTransfersOnly: sqlBool(true),
+	})
 	require.NoError(t, err)
 	require.Len(t, assetTransfers, 1)