remove mixtral-8x22b test (#1193)

Author: shuningjin

dags/sparsity_diffusion_devx/maxtext_moe_tpu_e2e.py

@@ -57,13 +57,7 @@
   }
 
   # Unchained tests
-  # TODO(ranran): add back ckpt conversation after b/384580048
   test_models_tpu = {
-      "mixtral-8x22b": {
-          "script_name": "tpu/mixtral/8x22b/2_test_mixtral",
-          "cluster": XpkClusters.TPU_V6E_256_MLPERF_CLUSTER,
-          "time_out_in_min": 90,
-      },
       "deepseek3-671b": {
           "script_name": "tpu/deepseek/v3-671b/2_test_deepseek",
           "cluster": XpkClusters.TPU_V5P_128_CLUSTER,