[bug#61117] Update svtplay-dl to 4.18

[Leo Famulari <leo@famulari.name>]

On Sun, Mar 05, 2023 at 09:15:14PM +0100, Jessica Tallon wrote:
> I think I have a mild opinion for having it bring in ffmpeg, this is
> mostly for three reasons:
> 
> - There isn't a good way to communicate to users that they might wish to
>   pull in ffmpeg.
>   
> - svtplay-dl will download both audio and video parts and then realise
>   it doesn't have ffmpeg and will give up producing a warning. This
>   leaves it up to the user to fix, while a merging both files is a
>   simple job it often has me searching through a manual as I'm not well
>   versed in ffmpeg or similar.
> 
> - I like it when things work consistantly (if x version of svtplay-dl
>   works a specific way on my machine, it should on another machine, not
>   dependent on my profile)
> 
> My preference is mild though, let me know what you think!

I think you should go with your method!