[ffmpeg/f31] (6 commits) ...Update to 4.2.1 release

Summary of changes: 60eebee... Make it build for el8 (*) e28ebe3... remove merged patch (*) 8691e6c... Add Br fribidi-devel (needed for el8) (*) 422a98b... Adjust el8 for availabe build requires (*) 149c1bd... Bump changelog (*) 0bc6257... Update to 4.2.1 release (*) (*) This commit already existed in another branch; no separate mail sent