symphony/orchestration: system allow to set latencies for all channels

symphony/orchestration/simbricks/orchestration/system/base.py

@@ -76,7 +76,11 @@ class System(util_base.IdObj):
         for chan in channels:
             chan.set_latency(amount, ratio)
 
-    def latencies(self, amount: int, ratio: util_base.Time, channel_type: tp.Any) -> None:
+    def latencies(
+        self, amount: int, ratio: util_base.Time, channel_type: tp.Any | None = None
+    ) -> None:
+        relevant_channels = self._all_channels
+        if channel_type:
             relevant_channels = list(
                 filter(
                     lambda chan: util_base.check_type(chan, channel_type),