FFmpeg 9.0.2-1794574081-946fcce07b

Build Linux packages on Ubuntu 24.04 with dav1d

Build the Linux packages in an ubuntu:24.04 container instead of Arch, so FFmpeg is configured
against libva 2.20 and does not use vaMapBuffer2 (libva 2.21+). Programs linking these packages
then run on any system with libva 2.20 or newer.

Add a static dav1d 1.5.4 for the AV1 decoder and merge it into libavcodec. Fetch the Vulkan and
nv-codec headers from git, as Ubuntu's are too old for FFmpeg's Vulkan hwaccels.

Only the Linux targets are built; other platforms stay on crueter-ci/FFmpeg.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>