fix: reset group permission checkboxes when creating a new API token

The group-level "select all" checkboxes (e.g. "Labels", "Backgrounds")
were not reset after creating a token, causing them to appear visually
checked when opening the form again even though the individual
permissions were unchecked.

Ref: https://community.vikunja.io/t/token-creation-malfunction-in-ticking-system/4318

frontend/src/views/user/settings/ApiTokens.vue

@@ -72,6 +72,7 @@ onMounted(async () => {
 
 function resetPermissions() {
 	newTokenPermissions.value = {}
+	newTokenPermissionsGroup.value = {}
 	Object.entries(availableRoutes.value).forEach(entry => {
 		const [group, routes] = entry
 		newTokenPermissions.value[group] = {}