feat: simplify DB further (#13771)

codex-rs/core/src/memories/tests.rs

@@ -474,7 +474,6 @@ mod phase2 {
             let state_db = codex_state::StateRuntime::init(
                 config.codex_home.clone(),
                 config.model_provider_id.clone(),
-                None,
             )
             .await
             .expect("initialize state db");
@@ -857,7 +856,6 @@ mod phase2 {
         let state_db = codex_state::StateRuntime::init(
             config.codex_home.clone(),
             config.model_provider_id.clone(),
-            None,
         )
         .await
         .expect("initialize state db");