Update gptoss-fp4-mi355x-vllm vLLM image to v0.21.0

Ref #1154

Co-authored-by: Klaud Cold <Klaud-Cold@users.noreply.github.com>

Author: github-actions[bot]

.github/configs/amd-master.yaml

@@ -752,7 +752,7 @@ gptoss-fp4-mi325x-vllm:
       - { tp: 8, conc-start: 4, conc-end: 16 }
 
 gptoss-fp4-mi355x-vllm:
-  image: vllm/vllm-openai-rocm:v0.17.0
+  image: vllm/vllm-openai-rocm:v0.21.0
   model: amd/gpt-oss-120b-w-mxfp4-a-fp8
   model-prefix: gptoss
   runner: mi355x

perf-changelog.yaml

@@ -2493,3 +2493,9 @@
     - "Update image tag to vllm/vllm-openai:v0.20.2"
     - "Add DEP configs for B300 vLLM MTP"
   pr-link: https://github.com/SemiAnalysisAI/InferenceX/pull/1271
+
+- config-keys:
+    - gptoss-fp4-mi355x-vllm
+  description:
+    - "Update vLLM ROCm image from v0.17.0 to v0.21.0"
+  pr-link: XXX