Bump ffmpeg-source from 44a0148 to 96f646c

Bumps [ffmpeg-source](https://github.com/FFmpeg/FFmpeg) from `44a0148` to `96f646c`.
- [Commits](FFmpeg/FFmpeg@44a0148...96f646c)

---
updated-dependencies:
- dependency-name: ffmpeg-source
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>