chore: empty string to represent real empty to

packages/vuetify/src/composables/router.tsx

@@ -64,9 +64,15 @@ export function useLink (props: LinkProps & LinkListeners, attrs: SetupContext['
       href: toRef(props, 'href'),
     }
   }
-
   // vue-router useLink `to` prop needs to be reactive and useLink will crash if undefined
-  const link = computed(() => props.to ? RouterLink.useLink(props as UseLinkOptions) : undefined)
+  const linkProps = computed(() => ({
+    ...props,
+    to: toRef(() => props.to || ''),
+  }))
+
+  const routerLink = RouterLink.useLink(linkProps.value as UseLinkOptions)
+  // Actual link needs to be undefined when to prop is not used
+  const link = computed(() => props.to ? routerLink : undefined)
 
   const route = useRoute()