Revert "settings: Remove auxiliary Content types where possible (#16744)" (#17768)

This breaks setting `{"scrollbar": {"show":"never"}}`
Release Notes:

- N/A

crates/zed/src/zed.rs

@@ -1996,7 +1996,7 @@ mod tests {
             cx.update_global::<SettingsStore, _>(|store, cx| {
                 store.update_user_settings::<WorktreeSettings>(cx, |project_settings| {
                     project_settings.file_scan_exclusions =
-                        vec!["excluded_dir".to_string(), "**/.git".to_string()];
+                        Some(vec!["excluded_dir".to_string(), "**/.git".to_string()]);
                 });
             });
         });