fix: support Gemini 3's thought signatures (#5806)

Signed-off-by: Salvatore Testa <sal@withpersona.com>

crates/goose/src/security/security_inspector.rs

@@ -113,6 +113,7 @@ mod tests {
                 name: "shell".into(),
                 arguments: Some(object!({"command": "rm -rf /"})),
             }),
+            thought_signature: None,
         }];
 
         let results = inspector.inspect(&tool_requests, &[]).await.unwrap();