[aubio] fix features

[mcmtroffaes]

• What does your PR fix?

  Whilst checking ffmpeg's dependents in vcpkg, I noticed that aubio was not functional, and could not read any audio files, and moreover that it dependent on far more features of ffmpeg than required. This PR addresses both problems. Before patch:

  $ ./installed/x64-linux/tools/aubio/aubiopitch ...
  AUBIO ERROR: source: failed creating with ... at 0Hz with hop size 256 (no source built-in)
  Error: could not open input file ...
  

  After patch:

  $ ./installed/x64-linux/tools/aubio/aubiopitch ...
  [output as expected]
  

• Which triplets are supported/not supported? Have you updated the CI baseline?

  No changes.

• Does your PR follow the maintainer guide?

  Yes, to the best of my knowledge.

• If you have added/updated a port: Have you run ./vcpkg x-add-version --all and committed the result?

  Yes.

[mcmtroffaes]

... for reviewer reference, here are all of the ffmpeg library imports in aubio: https://github.com/aubio/aubio/blob/master/src/io/source_avcodec.c#L23

[mcmtroffaes]

Oh, I should look more carefully at past PRs... This is a near duplicate of #17353 except for reducing the ffmpeg dependencies bit. Happy to wait for #17353 to be merged first, I'll then rebase this PR for the ffmpeg dependencies.

[mcmtroffaes]

Made some suggestions on other PR, since changes are so minimal, I think I can close this.