Speed up tests with pytest-xdist (#114)

* added pytest-xdist dependency and automatic use of -n auto

* disabled automatic multithreading in local tests, and enabled it when running github tests action

Author: EtayLivne

.github/workflows/tests.yaml

@@ -36,4 +36,4 @@ jobs:
           pip install '.[test]'
       - name: Run the tests with pytest
         run: |
-          python -m pytest --cov=posteriors --cov-report term-missing
+          python -m pytest -n auto --cov=posteriors --cov-report term-missing

pyproject.toml

@@ -17,7 +17,7 @@ classifiers = [
 dependencies = ["torch>=2.0.0", "torchopt>=0.7.3", "optree>=0.10.0"]
 
 [project.optional-dependencies]
-test = ["pre-commit", "pytest-cov", "ruff"]
+test = ["pre-commit", "pytest-cov", "pytest-xdist", "ruff"]
 docs = ["mkdocs", "mkdocs-material", "mkdocstrings[python]"]
 
 [tool.setuptools]
@@ -33,6 +33,7 @@ packages = [
 [tool.ruff.lint.per-file-ignores]
 "__init__.py" = ["F401", "F821", "E402"]
 
+
 [build-system]
 requires = ["setuptools>=64"]
 build-backend = "setuptools.build_meta"