enhance(frontend): URL入力フォームのtypeをurlに

Resolve #12137

packages/frontend/src/pages/admin/roles.editor.vue

@@ -21,7 +21,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 		<template #label>{{ i18n.ts.color }}</template>
 	</MkColorInput>
 
-	<MkInput v-model="role.iconUrl">
+	<MkInput v-model="role.iconUrl" type="url">
 		<template #label>{{ i18n.ts._role.iconUrl }}</template>
 	</MkInput>