Fix missing module

Author: xuedinge233

.github/workflows/_ascend_npu_torchtitan.yml

@@ -118,6 +118,7 @@ jobs:
         working-directory: torchtitan
         run: |
           mkdir artifacts-to-be-uploaded
+          pip install tokenizers
           python -m tests.integration_tests.run_tests --test_name artifacts-to-be-uploaded --ngpu ${{ steps.check_npu.outputs.npu_count }} || true
   
       - name: Run torchtitan unittest