revert change to -n

Author: nitins17

ci/run_pytest_gpu.sh

@@ -44,7 +44,7 @@ export TF_CPP_MIN_LOG_LEVEL=0
 echo "Running GPU tests..."
 export XLA_PYTHON_CLIENT_ALLOCATOR=platform
 export XLA_FLAGS=--xla_gpu_force_compilation_parallelism=1
-"$JAXCI_PYTHON" -m pytest -n 4 --tb=short --maxfail=20 \
+"$JAXCI_PYTHON" -m pytest -n 8 --tb=short --maxfail=20 \
 tests examples \
 --deselect=tests/multi_device_test.py::MultiDeviceTest::test_computation_follows_data \
 --deselect=tests/xmap_test.py::XMapTest::testCollectivePermute2D \