Fix DataCrunchCompute exception when terminating already removed instance (#3032)

Author: r4victor

src/dstack/_internal/core/backends/datacrunch/compute.py

@@ -161,7 +161,10 @@ def terminate_instance(
         try:
             self.client.instances.action(id_list=[instance_id], action="delete")
         except APIException as e:
-            if e.message == "Invalid instance id":
+            if e.message in [
+                "Invalid instance id",
+                "Can't discontinue a discontinued instance",
+            ]:
                 logger.debug("Skipping instance %s termination. Instance not found.", instance_id)
                 return
             raise