Stop skipping unresourced scene slots when seeding

0.5.0 seeds a scene slot whose package config names no resource with the absent
resource tag instead of refusing the object, so the flag check here now hides a
seed row the runtime expects. The flag stays on the slot: it is the only place
that separates a scene authored without a resource from one whose resource could
not be read.

Sunrise/src/state/activity_sdk/activity_sdk_seeds.cpp

@@ -407,10 +407,6 @@ AuthoredSceneSeedStatus materialize_authored_scene_seeds(const Catalog& catalog,
             || (slot.flags & format::kSlotSchemaJoinExact) == 0) {
             return AuthoredSceneSeedStatus::schemaMismatch;
         }
-        // A scene authored without a resource has nothing to seed; it is not a missing one.
-        if ((slot.flags & format::kSlotAuthoredSceneUnresourced) != 0) {
-            continue;
-        }
 
         const auto resources = slot_authored_scene_resources(catalog, slot);
         if (resources.empty()) {
@@ -436,8 +432,7 @@ AuthoredSceneSeedStatus materialize_authored_scene_seeds(const Catalog& catalog,
     std::size_t written = 0;
     for (const format::Slot& slot : slots) {
         if (slot.slotType != format::kAuthoredSceneSlotType
-            || slot.componentClass == format::kAbsentIndex
-            || (slot.flags & format::kSlotAuthoredSceneUnresourced) != 0) {
+            || slot.componentClass == format::kAbsentIndex) {
             continue;
         }
         const auto resources = slot_authored_scene_resources(catalog, slot);