Replace libsox with stub library

[mthrok]

This commit updates the way libsox is integrated to torchaudio

1. We stop statically linking libsox, so torchaudio will not ship libsox.
2. We link libsox dynamically. Users are expected to install libsox by themselves.
3. We use stab library to build torchaudio.

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/audio/3497

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

❌ 1 New Failure, 3 Unrelated Failures

As of commit 38d3923:

NEW FAILURE - The following job has failed:

• build (3.8) (gh)

BROKEN TRUNK - The following jobs failed but were present on the merge base 29903c5:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• tests (3.10, 11.8) / linux-job (gh)
• tests (3.8, 11.8) / linux-job (gh)
• tests (3.9, 11.8) / linux-job (gh)

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[facebook-github-bot]

@mthrok has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@mthrok has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@mthrok has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@mthrok has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@mthrok has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@mthrok merged this pull request in 8588fba.

[github-actions]

Hey @mthrok.
You merged this PR, but labels were not properly added. Please add a primary and secondary label (See https://github.com/pytorch/audio/blob/main/.github/process_commit.py).

---

Some guidance:

Use 'module: ops' for operations under 'torchaudio/{transforms, functional}', and ML-related components under 'torchaudio/csrc' (e.g. RNN-T loss).

Things in "examples" directory:

• 'recipe' is applicable to training recipes under the 'examples' folder,
• 'tutorial' is applicable to tutorials under the “examples/tutorials” folder
• 'example' is applicable to everything else (e.g. C++ examples)
• 'module: docs' is applicable to code documentations (not to tutorials).

Regarding examples in code documentations, please also use 'module: docs'.

Please use 'other' tag only when you’re sure the changes are not much relevant to users, or when all other tags are not applicable. Try not to use it often, in order to minimize efforts required when we prepare release notes.

---

When preparing release notes, please make sure 'documentation' and 'tutorials' occur as the last sub-categories under each primary category like 'new feature', 'improvements' or 'prototype'.

Things related to build are by default excluded from the release note, except when it impacts users. For example:
* Drop support of Python 3.7.
* Add support of Python 3.X.
* Change the way a third party library is bound (so that user needs to install it separately).