yt-dlp allows `--exec` command injection when using placeholder on Windows

yt-dlp is a feature-rich command-line audio/video downloader. In versions 2025.06.25 and below, when the --exec option is used on Windows with the default placeholder (or {}), insufficient sanitization is applied to the expanded filepath, allowing for remote code execution. This is a bypass of the mitigation for CVE-2024-22423 where the default placeholder and {} were not covered by the new escaping rules. Windows users who are unable to upgrade should avoid using --exec altogether. Instead, the --write-info-json or --dump-json options could be used, with an external script or command line consuming the JSON output. This is fixed in version 2025.07.21.