Revert "[codex-backend] Make thread metadata updates tolerate pending backfill" (#16923)

Reverts openai/codex#16877

codex-rs/app-server/src/codex_message_processor.rs

@@ -2754,24 +2754,6 @@ impl CodexMessageProcessor {
         if state_db_ctx.is_none() {
             state_db_ctx = get_state_db(&self.config).await;
         }
-        if state_db_ctx.is_none() {
-            match StateRuntime::init(
-                self.config.sqlite_home.clone(),
-                self.config.model_provider_id.clone(),
-            )
-            .await
-            {
-                Ok(ctx) => {
-                    state_db_ctx = Some(ctx);
-                }
-                Err(err) => {
-                    warn!(
-                        "failed to initialize state db for thread metadata update at {}: {err}",
-                        self.config.sqlite_home.display()
-                    );
-                }
-            }
-        }
         let Some(state_db_ctx) = state_db_ctx else {
             self.send_internal_error(
                 request_id,