remove ephemeral flag from codex-args in LLM security scan workflow

Author: 0xNeshi

.github/workflows/llm-security-scan.yml

@@ -80,7 +80,6 @@ jobs:
           # Extra CLI args forwarded to `codex exec`
           codex-args: >-
             --ask-for-approval never
-            --ephemeral
 
           prompt: |
             You are an expert application security auditor.