fix namespaces failing to emit

packages/emitter/src/emitter.ts

···
     const hasScalars = ns.scalars.size > 0;
     const hasUnions = ns.unions?.size > 0;
     const hasOperations = ns.operations?.size > 0;
-    const hasChildNamespaces = ns.namespaces.size > 0;
     const hasContent = hasModels || hasScalars || hasUnions;
 
     if (hasOperations) {
       return "operation";
     }
 
-    if (hasContent && hasChildNamespaces) {
-      return "defs";
-    }
-
-    if (hasContent && !hasChildNamespaces) {
+    if (hasContent) {
       return "content";
     }