[youtube] Remove the nondash formats (fixes #5774)
Since we use fixed values for some fields like width and height they can be wrong, and would get picked by some formats filters.
For example for https://www.youtube.com/watch?v=EQCrhbBxsjA the biggest height is 720 and for nondash formats it's set to 1440, so -f 'bestvideo[height>=1200]+bestaudio' would incorrectly pick the nondash format, instead it should report that the requested format is not available.