Enable React Native strict TypeScript API (#11459)

src/alf/util/dimensions.ts

@@ -1,5 +1,5 @@
 import {useEffect, useState} from 'react'
-import {Dimensions} from 'react-native'
+import {Dimensions, type DimensionsPayload} from 'react-native'
 
 /**
  * Same as `useWindowDimensions().fontScale`, but avoids rerendering
@@ -9,9 +9,12 @@ export function useNativeFontScale() {
   const [fontScale, setFontScale] = useState(Dimensions.get('window').fontScale)
 
   useEffect(() => {
-    const sub = Dimensions.addEventListener('change', evt => {
-      setFontScale(evt.window.fontScale)
-    })
+    const sub = Dimensions.addEventListener(
+      'change',
+      (evt: DimensionsPayload) => {
+        if (evt.window) setFontScale(evt.window.fontScale)
+      },
+    )
     return () => sub.remove()
   }, [])