[BUG]windows下载歌词的编码问题

1.windows下载歌词时因为gbk编码出错
2.如果一起下载歌曲，封面，歌词，歌词因为1的原因下载出错会影响后面封面的下载

Look at the lyric download code in the music-dl CLI tool, likely in a module handling downloads or network requests. The issue mentions Windows and GBK encoding errors, so check how file encoding is set when saving lyrics. Test by running the tool on Windows or simulating the encoding mismatch, then ensure lyrics are saved with UTF-8 or proper encoding to prevent failure from blocking subsequent cover downloads.

索引モデルが issue の本文から書いたものです。