Remove unittest main blocks

They are not necessary with tox, and reduce coverage slightly.

Author: stephane-caron

tests/test_descriptions.py

@@ -55,7 +55,3 @@ def test_all_descriptions(self):
                     f"Meshes path {description.MESHES_PATH} does not exist "
                     f"in {description}",
                 )
-
-
-if __name__ == "__main__":
-    unittest.main()

tests/test_git.py

@@ -100,7 +100,3 @@ def test_progress_bar(self):
         bar.update(0, 42, 42)
         self.assertEqual(bar.progress.n, 42)
         self.assertEqual(bar.progress.total, 42)
-
-
-if __name__ == "__main__":
-    unittest.main()