Fix formatting: use f-strings for consistency

Author: aws-jasakshi

jupyter_server/services/contents/filemanager.py

@@ -603,7 +603,7 @@ def rename_file(self, old_path, new_path):
         except web.HTTPError:
             raise
         except FileNotFoundError:
-            raise web.HTTPError(404, "File or directory does not exist: %s" % old_path)
+            raise web.HTTPError(404, f"File or directory does not exist: {old_path}")
         except Exception as e:
             raise web.HTTPError(500, f"Unknown error renaming file: {old_path} {e}") from e
 
@@ -1072,7 +1072,7 @@ async def rename_file(self, old_path, new_path):
         except web.HTTPError:
             raise
         except FileNotFoundError:
-            raise web.HTTPError(404, "File or directory does not exist: %s" % old_path)
+            raise web.HTTPError(404, f"File or directory does not exist: {old_path}")
         except Exception as e:
             raise web.HTTPError(500, f"Unknown error renaming file: {old_path} {e}") from e