fix(useScroll): trigger once onMounted to get correct inital arrive…

…dStates values (#3384)

Co-authored-by: Anthony Fu <anthonyfu117@hotmail.com>

packages/core/useScroll/index.ts

@@ -1,6 +1,6 @@
 import { computed, reactive, ref } from 'vue-demi'
 import type { MaybeRefOrGetter } from '@vueuse/shared'
-import { noop, toValue, useDebounceFn, useThrottleFn } from '@vueuse/shared'
+import { noop, toValue, tryOnMounted, useDebounceFn, useThrottleFn } from '@vueuse/shared'
 import { useEventListener } from '../useEventListener'
 import type { ConfigurableWindow } from '../_configurable'
 import { defaultWindow } from '../_configurable'
@@ -250,6 +250,10 @@ export function useScroll(
     eventListenerOptions,
   )
 
+  tryOnMounted(() => {
+    setArrivedState(toValue(element))
+  })
+
   useEventListener(
     element,
     'scrollend',