The yt-dlp project, a YouTube video downloader, will soon require a JavaScript runtime like Deno to be installed in order to download videos from YouTube due to changes in YouTube's player JavaScript. This change is necessary because the current native JavaScript interpreter in yt-dlp is no longer sufficient to handle the new JavaScript challenges. The project recommends installing Deno, but other JavaScript runtimes like Node, Bun, and QuickJS will also be supported. Users will need to take action to install the required JavaScript runtime and possibly update their yt-dlp installation.