Fix currentSiteStage function

Fix new error handling

src/isar_exr/api/energy_robotics_api.py

@@ -703,8 +703,16 @@ def get_current_site_stage(self, site_id: str) -> str:
 
         params: dict = {"siteId": site_id}
 
-        response_dict: dict[str, Any] = self.client.query(
-            dsl_gql(current_site_stage_query), params
-        )
-
-        return response_dict["currentSiteStage"]["id"]
+        try:
+            response_dict: dict[str, Any] = self.client.query(
+                dsl_gql(current_site_stage_query), params
+            )
+        except Exception as e:
+            message: str = "Could not get current site stage"
+            self.logger.error(message)
+            raise RobotAPIException(
+                error_description=message,
+            )
+        if response_dict["currentSiteStage"] is not None:
+            return response_dict["currentSiteStage"]["id"]
+        return None

src/isar_exr/robotinterface.py

@@ -85,6 +85,9 @@ def __init__(self) -> None:
         )
 
     def initiate_mission(self, mission: Mission) -> None:
+        curent_stage_id = self.api.get_current_site_stage(settings.ROBOT_EXR_SITE_ID)
+        if curent_stage_id is not None:
+            self.api.discard_stage(stage_id=curent_stage_id)
         stage_id: str = self.api.create_stage(site_id=settings.ROBOT_EXR_SITE_ID)
         poi_ids: List[str] = []
         for task in mission.tasks: