Make clippy happy

Author: bjorn3

src/bootstrap/src/core/build_steps/compile.rs

@@ -2138,7 +2138,7 @@ pub fn run_cargo(
         .collect::<Vec<_>>();
     for (prefix, extension, expected_len) in toplevel {
         let candidates = contents.iter().filter(|&(_, filename, meta)| {
-            expected_len.map_or(true, |expected_len| meta.len() == expected_len)
+            expected_len.is_none_or(|expected_len| meta.len() == expected_len)
                 && filename
                     .strip_prefix(&prefix[..])
                     .map(|s| s.starts_with('-') && s.ends_with(&extension[..]))