[CI/Build] Rework CPU multimodal processor test (#29684)

Signed-off-by: Isotr0py <mozf@mail2.sysu.edu.cn>

.buildkite/test-pipeline.yaml

@@ -820,14 +820,24 @@ steps:
   commands:
     - pytest -v -s models/language/pooling_mteb_test
 
-- label: Multi-Modal Processor Test # 44min
+- label: Multi-Modal Processor Test (CPU)
+  timeout_in_minutes: 60
+  source_file_dependencies:
+  - vllm/
+  - tests/models/multimodal
+  no_gpu: true
+  commands:
+    - pip install git+https://github.com/TIGER-AI-Lab/Mantis.git
+    - pytest -v -s models/multimodal/processing --ignore models/multimodal/processing/test_tensor_schema.py
+
+- label: Multi-Modal Processor Test
   timeout_in_minutes: 60
   source_file_dependencies:
   - vllm/
   - tests/models/multimodal
   commands:
     - pip install git+https://github.com/TIGER-AI-Lab/Mantis.git
-    - pytest -v -s models/multimodal/processing
+    - pytest -v -s models/multimodal/processing/test_tensor_schema.py
 
 - label: Multi-Modal Models Test (Standard) # 60min
   timeout_in_minutes: 80