Debian arm64 unable to run

This was reported in the Owncast chat.

```
root@owncast2:/opt/ffmpeg# ./ffmpeg 
./ffmpeg: error while loading shared libraries: libmvec.so.1: cannot open shared object file: No such file or directory
root@owncast2:/opt/ffmpeg# uname -a
Linux owncast2 6.1.0-31-arm64 #1 SMP Debian 6.1.128-1 (2025-02-07) aarch64 GNU/Linux
root@owncast2:/opt/ffmpeg# 
```