[JAX] XLA_FLAG to WAR the current NCCL issue with test_distributed_softmax.py (#2378)

* add war for test_distributed_softmax.py
Signed-off-by: Phuong Nguyen <phuonguyen@nvidia.com>

---------
Signed-off-by: Phuong Nguyen <phuonguyen@nvidia.com>

qa/L1_jax_distributed_unittest/test.sh

@@ -28,7 +28,9 @@ python3 -m pytest -c $TE_PATH/tests/jax/pytest.ini -v --junitxml=$XML_LOG_DIR/py
 
 python3 -m pytest -c $TE_PATH/tests/jax/pytest.ini -v --junitxml=$XML_LOG_DIR/pytest_dist_mlp.xml $TE_PATH/tests/jax/test_distributed_layernorm_mlp.py || test_fail "test_distributed_layernorm_mlp.py"
 
-python3 -m pytest -c $TE_PATH/tests/jax/pytest.ini -v --junitxml=$XML_LOG_DIR/pytest_dist_softmax.xml $TE_PATH/tests/jax/test_distributed_softmax.py || test_fail "test_distributed_softmax.py"
+# XLA_FLAGS to WAR for test_distributed_softmax issue with NCCL
+# TODO(Kshitij): remove when NCCL issue is fixed
+XLA_FLAGS="$XLA_FLAGS --xla_gpu_enable_nccl_comm_splitting=false" python3 -m pytest -c $TE_PATH/tests/jax/pytest.ini -v --junitxml=$XML_LOG_DIR/pytest_dist_softmax.xml $TE_PATH/tests/jax/test_distributed_softmax.py || test_fail "test_distributed_softmax.py"
 
 python3 -m pytest -c $TE_PATH/tests/jax/pytest.ini -v --junitxml=$XML_LOG_DIR/pytest_dist_fused_attn.xml $TE_PATH/tests/jax/test_distributed_fused_attn.py || test_fail "test_distributed_fused_attn.py"