add compression to the pip-sdist step

Author: patapenka-alexey

Makefile

@@ -44,7 +44,7 @@ docs:
 
 .PHONY: pip-sdist
 pip-sdist:
-	python3 setup.py sdist --dist-dir=pip_dist
+	python3 setup.py sdist --dist-dir=pip_dist --formats=xztar
 
 .PHONY: pip-bdist
 pip-bdist: