Removed the "remote_compaction" feature flag (#10840)

This feature is always on now

codex-rs/app-server/tests/suite/v2/compaction.rs

@@ -29,7 +29,6 @@ use codex_app_server_protocol::TurnStartParams;
 use codex_app_server_protocol::TurnStartResponse;
 use codex_app_server_protocol::UserInput as V2UserInput;
 use codex_core::auth::AuthCredentialsStoreMode;
-use codex_core::features::Feature;
 use codex_protocol::models::ContentItem;
 use codex_protocol::models::ResponseItem;
 use core_test_support::responses;
@@ -143,12 +142,10 @@ async fn auto_compaction_remote_emits_started_and_completed_items() -> Result<()
     .await;
 
     let codex_home = TempDir::new()?;
-    let mut features = BTreeMap::default();
-    features.insert(Feature::RemoteCompaction, true);
     write_mock_responses_config_toml(
         codex_home.path(),
         &server.uri(),
-        &features,
+        &BTreeMap::default(),
         AUTO_COMPACT_LIMIT,
         Some(true),
         "openai",