Removed experimental "command risk assessment" feature (#7799)

This experimental feature received lukewarm reception during internal
testing. Removing from the code base.

codex-rs/app-server-test-client/src/main.rs

@@ -756,7 +756,6 @@ impl CodexClient {
             turn_id,
             item_id,
             reason,
-            risk,
             proposed_execpolicy_amendment,
         } = params;
 
@@ -766,9 +765,6 @@ impl CodexClient {
         if let Some(reason) = reason.as_deref() {
             println!("< reason: {reason}");
         }
-        if let Some(risk) = risk.as_ref() {
-            println!("< risk assessment: {risk:?}");
-        }
         if let Some(execpolicy_amendment) = proposed_execpolicy_amendment.as_ref() {
             println!("< proposed execpolicy amendment: {execpolicy_amendment:?}");
         }