Fix zauberzeug#5293

Author: python-and-novella

nicegui/elements/aggrid/aggrid.js

@@ -5,7 +5,7 @@ export default {
   template: "<div></div>",
   mounted() {
     this.update_grid();
-
+    this.$el.setAttribute("data-ag-theme-mode", document.body.classList.contains("body--dark") ? "dark" : "light")
     this.themeObserver = new MutationObserver(() =>
       this.$el.setAttribute("data-ag-theme-mode", document.body.classList.contains("body--dark") ? "dark" : "light")
     );