Fix possible unhandled IQVIA exception with allergy outlook data (#54477)

Co-authored-by: Joakim Sørensen <hi@ludeeus.dev>

homeassistant/components/iqvia/sensor.py

@@ -104,7 +104,7 @@ class ForecastSensor(IQVIAEntity):
     @callback
     def update_from_latest_data(self):
         """Update the sensor."""
-        if not self.coordinator.data:
+        if not self.available:
             return
 
         data = self.coordinator.data.get("Location", {})
@@ -120,6 +120,7 @@ class ForecastSensor(IQVIAEntity):
             if i["minimum"] <= average <= i["maximum"]
         ]
 
+        self._attr_state = average
         self._attr_extra_state_attributes.update(
             {
                 ATTR_CITY: data["City"].title(),
@@ -134,6 +135,10 @@ class ForecastSensor(IQVIAEntity):
             outlook_coordinator = self.hass.data[DOMAIN][DATA_COORDINATOR][
                 self._entry.entry_id
             ][TYPE_ALLERGY_OUTLOOK]
+
+            if not outlook_coordinator.last_update_success:
+                return
+
             self._attr_extra_state_attributes[
                 ATTR_OUTLOOK
             ] = outlook_coordinator.data.get("Outlook")
@@ -141,8 +146,6 @@ class ForecastSensor(IQVIAEntity):
                 ATTR_SEASON
             ] = outlook_coordinator.data.get("Season")
 
-        self._attr_state = average
-
 
 class IndexSensor(IQVIAEntity):
     """Define sensor related to indices."""