build(deps): bump ffmpeg_sources/AMF from 6d7bec0 to 3588c60 (#358)

Bumps [ffmpeg_sources/AMF](https://github.com/GPUOpen-LibrariesAndSDKs/AMF) from `6d7bec0` to `3588c60`.
- [Release notes](https://github.com/GPUOpen-LibrariesAndSDKs/AMF/releases)
- [Commits](GPUOpen-LibrariesAndSDKs/AMF@6d7bec0...3588c60)

---
updated-dependencies:
- dependency-name: ffmpeg_sources/AMF
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>