fix: remove redundant image markdown from v3.28.6 release notes

Author: hannesrudolph

docs/update-notes/v3.28.6.mdx

@@ -14,7 +14,6 @@ image: /img/v3.28.6/v3.28.6.png
 This release adds GPT-5-Codex to OpenAI Native, sharpens localization coverage, and smooths UI workflows across languages.
 
 <img src="/img/v3.28.6/v3.28.6.png" alt="Roo Code v3.28.6 Release" width="600" />
-![alt text](../../static/img/v3.28.6/v3.28.6.png)
 
 ## GPT-5-Codex lands in OpenAI Native