uucore: format: Use .into_owned() for from_utf8_lossy()

Suggested by Gemini and I think that's not a bad idea.

src/uucore/src/lib/features/format/argument.rs

@@ -159,7 +159,7 @@ impl<'a> FormatArguments<'a> {
         if bytes.len() > len {
             return Err(ExtendedParserError::PartialMatch(
                 val,
-                String::from_utf8_lossy(&bytes[len..]).to_string(),
+                String::from_utf8_lossy(&bytes[len..]).into_owned(),
             ));
         }