fix(types): avoid circular type inference between v2 and v3 instance types

fix #12683

Author: yyx990803

Diff for: types/v3-component-public-instance.d.ts

@@ -179,9 +179,7 @@ interface Vue3Instance<
         ? Partial<Defaults> & Omit<P & PublicProps, keyof Defaults>
         : P & PublicProps
     >,
-    ComponentPublicInstance | null,
     ComponentPublicInstance,
-    ComponentPublicInstance[],
     Options & MergedComponentOptionsOverride,
     EmitFn<E>
   > {}

Diff for: types/vue.d.ts

@@ -14,7 +14,6 @@ import { VNode, VNodeData, VNodeChildren, NormalizedScopedSlot } from './vnode'
 import { PluginFunction, PluginObject } from './plugin'
 import { DefineComponent } from './v3-define-component'
 import { nextTick } from './v3-generated'
-import { ComponentPublicInstance } from './v3-component-public-instance'
 
 export interface CreateElement {
   (
@@ -41,29 +40,27 @@ type NeverFallback<T, D> = [T] extends [never] ? D : T
 export interface Vue<
   Data = Record<string, any>,
   Props = Record<string, any>,
-  Parent = never,
-  Root = never,
-  Children = never,
+  Instance = never,
   Options = never,
   Emit = (event: string, ...args: any[]) => Vue
 > {
   // properties with different types in defineComponent()
   readonly $data: Data
   readonly $props: Props
-  readonly $parent: NeverFallback<Parent, Vue>
-  readonly $root: NeverFallback<Root, Vue>
-  readonly $children: NeverFallback<Children, Vue[]>
+  readonly $parent: NeverFallback<Instance, Vue> | null
+  readonly $root: NeverFallback<Instance, Vue>
+  readonly $children: NeverFallback<Instance, Vue>[]
   readonly $options: NeverFallback<Options, ComponentOptions<Vue>>
   $emit: Emit
 
   // Vue 2 only or shared
   readonly $el: Element
   readonly $refs: {
     [key: string]:
+      | NeverFallback<Instance, Vue>
       | Vue
       | Element
-      | ComponentPublicInstance
-      | (Vue | Element | ComponentPublicInstance)[]
+      | (NeverFallback<Instance, Vue> | Vue | Element)[]
       | undefined
   }
   readonly $slots: { [key: string]: VNode[] | undefined }