Update optimum-rbln to 0.9.5a6 (#288)

Author: rebel-develop

pyproject.toml

@@ -40,7 +40,7 @@ dependencies = [
     "datasets",
     "qwen_vl_utils",
     "vllm==0.10.2",
-    "optimum-rbln>=0.9.5a5",
+    "optimum-rbln>=0.9.5a6",
     "torch==2.8.0",
 ]