fix(rum): restrict traceHeaderOrigins to same origin to prevent matrix CORS preflight failure

public/index.html

@@ -11,7 +11,8 @@
     serviceName: "gibbz",
     baseUrl: "https://otel.k6n.net",
     release: window.__APP_RELEASE__ || "dev",
-    environment: "production"
+    environment: "production",
+    traceHeaderOrigins: [window.location.origin]
   }) : null;
 </script>
 </head>