Function list_log_files 

pub fn list_log_files(
    gctx: &GlobalContext,
    ws: Option<&Workspace<'_>>,
) -> CargoResult<Box<dyn Iterator<Item = (PathBuf, RunId)>>>

Lists log files by calling a callback for each valid log file.

• Yield log files from new to old
• If in a workspace, select only the log files associated with the workspace