Add parallel test target, using pytest-xdist

Makefile

@@ -95,7 +95,13 @@ sdist:
 .PHONY: test
 test:
 	python3 -c "import pytest" > /dev/null 2>&1 || python3 -m pip install pytest
-	python3 -m pytest -qq
+	python3 -m pytest -qq Tests/
+
+.PHONY: test-p
+test-p:
+	python3 -c "import xdist" > /dev/null 2>&1 || python3 -m pip install pytest-xdist
+	python3 -m pytest -qq -n auto Tests/
+
 
 .PHONY: valgrind
 valgrind:

pyproject.toml

@@ -70,6 +70,7 @@ optional-dependencies.tests = [
   "pytest",
   "pytest-cov",
   "pytest-timeout",
+  "pytest-xdist",
   "trove-classifiers>=2024.10.12",
 ]