fix check errors

src/ahriman/application/ahriman.py

@@ -274,7 +274,7 @@ def _set_web_parser(root: SubParserAction) -> argparse.ArgumentParser:
     return parser
 
 
-def run():
+def run() -> None:
     """
     run application instance
     """

src/ahriman/core/status/web_client.py

@@ -52,7 +52,8 @@ class WebClient(Client):
         :param exception: exception raised
         :return: text of the response if it is not None and empty string otherwise
         """
-        return exception.response.text if exception.response is not None else ''
+        result: str = exception.response.text if exception.response is not None else ''
+        return result
 
     def _ahriman_url(self) -> str:
         """