Windows CI Workflow FFmpeg taking too long to build

[jamylak]

This TODO comment about FFmpeg taking too long to build should be addressed or at least clarified with a tracking issue number. Consider investigating whether pre-built FFmpeg binaries can be used on Windows CI, or if caching vcpkg packages would help.

        # Note: FFmpeg is intentionally not built on Windows CI because building it from source via vcpkg
        #       significantly increases build time. If FFmpeg coverage is required in Windows CI in the future,
        #       prefer using pre-built FFmpeg binaries or cached vcpkg artifacts instead of enabling a full build here.

Originally posted by @Copilot in #31 (comment)

[jamylak]

will just ./configure a mini ffmpeg with --disable-everything --enable-thing-1 etc etc at some point