scripts/build_manylinux_in_docker.sh: use pytest instead of setup.py test

The latter fails on Python 3.13 since setuptools isn't installed by
default. If we need to install something anyways, we might as well use
the nicer pytest.

Signed-off-by: Omar Sandoval <osandov@osandov.com>

scripts/build_manylinux_in_docker.sh

@@ -97,7 +97,8 @@ for pybin in /opt/python/cp*/bin; do
 	if build_for_python "$pybin/python"; then
 		"$pybin/pip" install drgn --no-index -f /tmp/manylinux_wheels/
 		"$pybin/drgn" --version
-		"$pybin/python" setup.py test
+		"$pybin/pip" install pytest
+		"$pybin/pytest"
 	fi
 done