refactor: reduce redundant code

Author: wswmsword

src/hooks/useAutoThemeSwitcher.ts

@@ -3,10 +3,8 @@ import type { AppStore } from '@/stores/modules/app'
 export default function useAutoThemeSwitcher(appStore: AppStore) {
   const handleAttributeChange = () => {
     const rootElement = document.documentElement
-    if (rootElement.classList.contains('dark'))
-      appStore.switchMode('dark')
-    else
-      appStore.switchMode('light')
+    const mode = rootElement.classList.contains('dark') ? 'dark' : 'light'
+    appStore.switchMode(mode)
   }
 
   const observerOptions = {