fix: Make incremental artifact deletion more robust

Should fix the intermittent errors reported in #57958

cc #48614

src/librustc_incremental/persist/fs.rs

@@ -886,7 +886,10 @@ fn safe_remove_dir_all(p: &Path) -> io::Result<()> {
 fn safe_remove_file(p: &Path) -> io::Result<()> {
  if p.exists() {
  let canonicalized = p.canonicalize()?;
- std_fs::remove_file(canonicalized)
+ match std_fs::remove_file(canonicalized) {
+ Err(ref err) if err.kind() == io::ErrorKind::NotFound => Ok(()),
+ result => result,
+ }
  } else {
  Ok(())
  }