[VLM] Add max-count checking in data parser for single image models (#11661)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>
Signed-off-by: Roger Wang <ywang@roblox.com>
Co-authored-by: Roger Wang <ywang@roblox.com>

tests/multimodal/test_processing.py

@@ -622,10 +622,11 @@ def _test_processing_cache_correctness(
 
 
 # yapf: disable
+# True if the model supports multiple data items of the modality per request
 @pytest.mark.parametrize(("model_id", "modalities"), [
     ("rhymes-ai/Aria", {"image": True}),
     ("Salesforce/blip2-opt-2.7b", {"image": False}),
-    ("facebook/chameleon-7b", {"image": True}),
+    ("facebook/chameleon-7b", {"image": False}),
     ("adept/fuyu-8b", {"image": False}),
     ("llava-hf/llava-1.5-7b-hf", {"image": True}),
     ("TIGER-Lab/Mantis-8B-siglip-llama3", {"image": True}),