style: apply Ruff formatting

src/blackout_notifier/clients.py

@@ -114,14 +114,11 @@ class EitaaClient:
         try:
             body = response.json()
         except requests.JSONDecodeError as error:
-            raise ExternalServiceError(
-                f"Eitaa returned invalid JSON for chat {chat_id}"
-            ) from error
+            raise ExternalServiceError(f"Eitaa returned invalid JSON for chat {chat_id}") from error
         if not isinstance(body, dict) or body.get("ok") is not True:
             description = body.get("description") if isinstance(body, dict) else None
             raise ExternalServiceError(
-                f"Eitaa rejected the message for chat {chat_id}: "
-                f"{description or 'unknown error'}"
+                f"Eitaa rejected the message for chat {chat_id}: {description or 'unknown error'}"
             )