Release b8.0.1

upgrade to ffmpeg 8.0.1, switch to ncryptedV1 fork

- Update ffmpeg version from 6.1.1 to 8.0.1
- Switch Linux x64/arm64 builds from johnvansickle.com to BtbN/FFmpeg-Builds
  (johnvansickle only has 7.0.2, BtbN has 8.0)
- Update default download URL to ncryptedV1/ffmpeg-static releases
- Update macOS ARM64 source from ffmpeg6arm.zip to ffmpeg80arm.zip
- Keep johnvansickle.com for Linux ia32/armhf (BtbN doesn't support these)

Co-authored-by: Cursor <cursoragent@cursor.com>