fix(vModel): fix v-model being reset in updated

packages/runtime-dom/src/directives/vModel.ts

@@ -155,14 +155,16 @@ function setChecked(
   { value, oldValue }: DirectiveBinding,
   vnode: VNode,
 ) {
-  // store the v-model value on the element so it can be accessed by the
-  // change listener.
+  // #8638
+  if (value === oldValue)
+    return // store the v-model value on the element so it can be accessed by the
+    // change listener.
   ;(el as any)._modelValue = value
   if (isArray(value)) {
     el.checked = looseIndexOf(value, vnode.props!.value) > -1
   } else if (isSet(value)) {
     el.checked = value.has(vnode.props!.value)
-  } else if (value !== oldValue) {
+  } else {
     el.checked = looseEqual(value, getCheckboxValue(el, true))
   }
 }
@@ -216,8 +218,9 @@ export const vModelSelect: ModelDirective<HTMLSelectElement> = {
   beforeUpdate(el, _binding, vnode) {
     el[assignKey] = getModelAssigner(vnode)
   },
-  updated(el, { value, modifiers: { number } }) {
-    if (!el._assigning) {
+  updated(el, { value, oldValue, modifiers: { number } }) {
+    // #8579
+    if (!el._assigning && value !== oldValue) {
       setSelected(el, value, number)
     }
   },