Remove duplicate qwen3.5-fp8-mi355x-atom perf-changelog entry (#1296)

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: seungrokj

perf-changelog.yaml

@@ -1436,14 +1436,6 @@
     - "Image includes upstream SGLang PRs: https://github.com/sgl-project/sglang/pull/21188, https://github.com/sgl-project/sglang/pull/21421, https://github.com/sgl-project/sglang/pull/20736"
   pr-link: https://github.com/SemiAnalysisAI/InferenceX/pull/1036
 
-- config-keys:
-    - qwen3.5-fp8-mi355x-atom
-    - qwen3.5-fp8-mi355x-atom-mtp
-  description:
-    - "Add Qwen3.5-397B-A17B FP8 MI355X ATOM benchmark configs with and without MTP"
-  pr-link: https://github.com/SemiAnalysisAI/InferenceX/pull/1040
-
-
 - config-keys:
     - qwen3.5-fp4-mi355x-sglang
   description: