Make torchaudio an optional dependency #434

	# This workflow will install Python dependencies, run tests and lint with a variety of Python versions
	# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions

	name: missing_torchaudio

	on:
	push:
	branches: [ master ]
	pull_request:
	branches: [ master ]

	jobs:
	missing_torchaudio:

	runs-on: ubuntu-latest
	strategy:
	matrix:
	include:
	- python-version: "3.12"
	torch-install-cmd: "pip install torch==2.3 --index-url https://download.pytorch.org/whl/cpu"

	fail-fast: false

	steps:
	- uses: actions/checkout@v2
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v2
	with:
	python-version: ${{ matrix.python-version }}
	cache: pip
	cache-dependency-path: \|
	docs/requirements.txt
	setup.py
	- name: Install apt dependencies
	run: \|
	sudo apt update
	sudo apt install libsndfile1-dev libsndfile1 ffmpeg sox
	- name: Install Python dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install wheel numpy scipy
	# Force the installation of a CPU-only PyTorch
	${{ matrix.torch-install-cmd }}
	# the torchaudio env var does nothing when torchaudio is installed, but doesn't require it's presence when it's not
	LHOTSE_REQUIRE_TORCHAUDIO=0 pip install '.[tests]'
	- name: Run basic tests only for missing torchaudio case
	run: \|
	pytest test/test_missing_torchaudio.py

Provide feedback