Set MAX_CUDAGRAPH_CAPTURE_SIZE to 2048 unconditionally

Author: wzhao18

benchmarks/single_node/dsv4_fp4_b200_vllm.sh

@@ -54,11 +54,7 @@ else
     MAX_NUM_BATCHED_TOKENS=2048
 fi
 
-if [ "${ISL}" -eq 8192 ]; then
-    MAX_CUDAGRAPH_CAPTURE_SIZE=512
-else
-    MAX_CUDAGRAPH_CAPTURE_SIZE=2048
-fi
+MAX_CUDAGRAPH_CAPTURE_SIZE=2048
 
 BENCHMARK_MAX_MODEL_LEN="$MAX_MODEL_LEN"