Remove unnecessary entity fetches.

src/camera-manager/manager.ts

@@ -189,7 +189,8 @@ export class CameraManager {
       camerasConfig.some((config) => hasAutoTriggers(config))
     ) {
       // ... then we need to populate the entity cache by fetching all entities
-      // from Home Assistant.
+      // from Home Assistant. Do this once upfront, to avoid each camera doing
+      // it.
       await entityRegistryManager.fetchEntityList(hass);
     }