fix(RadioGroup): add missing fieldset config

Resolves #1472

src/runtime/components/forms/RadioGroup.vue

@@ -1,6 +1,6 @@
 <template>
   <div :class="ui.wrapper">
-    <fieldset v-bind="attrs">
+    <fieldset v-bind="attrs" :class="ui.fieldset">
       <legend v-if="legend || $slots.legend" :class="ui.legend">
         <slot name="legend">
           {{ legend }}

src/runtime/ui.config/forms/radioGroup.ts

@@ -1,7 +1,8 @@
 export default {
   wrapper: 'relative flex items-start',
+  fieldset: '',
   legend: 'text-sm font-medium text-gray-700 dark:text-gray-200 mb-1',
   default: {
     color: 'primary'
   }
-}
+}