ci: temporarily remove Codex Security from release scans #4466

User Story

I operate OpenShell tagged releases and repeatedly encounter Codex Security failures that block publication. I need to temporarily remove this scan from release qualification while scan reliability is investigated.

Description

Remove the Codex job from Security Scan and remove its unused inputs and secret from the parent and the Release Tag caller. Keep the standalone Codex workflow available for manual investigation. Other scanners, release qualification, publication and artifact handling retain their existing behavior.

Context

The first two Codex jobs in release run 38395728837 completed with partial coverage and exit code 2. This task covers the temporary removal from release scans; it does not resolve the underlying reliability problem.

Definition of Done

• Release security scans no longer invoke Codex Security.
• Unused Codex inputs and secrets are removed from the parent and release caller.
• Other scanners and release qualification/publication behavior are preserved.
• The standalone Codex workflow remains available manually.
• CI documentation reflects the temporary removal.