Update viewer.js

viewer.js

@@ -81,7 +81,7 @@ export async function initializeViewer(config, instanceId) {
   progressDialog.style.display = 'block';
 
   if (!pc) {
-    pc = await import("https://esm.run/playcanvas");
+    pc = await import("https://cdn.jsdelivr.net/npm/playcanvas/build/playcanvas.module.min.js");
     window.pc = pc;
   }