Eliminate a few React.Element type that will be synced to react-native (#30719)

Summary:
## Summary

Flow will eventually remove the specific `React.Element` type. For most
of the code, it can be replaced with `React.MixedElement` or
`React.Node`.

When specific react elements are required, it needs to be replaced with
either `React$Element` which will trigger a `internal-type` lint error
that can be disabled project-wide, or use
`ExactReactElement_DEPRECATED`.

Fortunately in this case, this one can be replaced with just
`React.MixedElement`.

## How did you test this change?

`flow`

DiffTrain build for commit https://github.com/facebook/react/commit/85fb95cdffdd95f2f908ee71974cae06b1c866e1.

bypass-github-export-checks

Reviewed By: poteto

Differential Revision: D61397212

Pulled By: SamChou19815

fbshipit-source-id: c0aa5a4ed3922f88b7e557738f76f872c02a9d07

packages/react-native/Libraries/Renderer/shims/ReactNativeTypes.js

@@ -7,10 +7,15 @@
  * @noformat
  * @nolint
  * @flow strict
- * @generated SignedSource<<4405023a5d82ddc01db31d8eb46a7aa0>>
+ * @generated SignedSource<<89361333bb6b688486e35849a9c669a6>>
  */
 
-import type {ElementRef, ElementType, Element, AbstractComponent} from 'react';
+import type {
+  ElementRef,
+  ElementType,
+  MixedElement,
+  AbstractComponent,
+} from 'react';
 
 export type MeasureOnSuccessCallback = (
   x: number,
@@ -222,7 +227,7 @@ export type ReactNativeType = {
     eventType: string,
   ): void,
   render(
-    element: Element<ElementType>,
+    element: MixedElement,
     containerTag: number,
     callback: ?() => void,
     options: ?RenderRootOptions,
@@ -257,7 +262,7 @@ export type ReactFabricType = {
     eventType: string,
   ): void,
   render(
-    element: Element<ElementType>,
+    element: MixedElement,
     containerTag: number,
     callback: ?() => void,
     concurrentRoot: ?boolean,

packages/react-native/Libraries/__tests__/__snapshots__/public-api-test.js.snap

@@ -7912,7 +7912,7 @@ export type ReactNativeType = {
     eventType: string
   ): void,
   render(
-    element: Element<ElementType>,
+    element: MixedElement,
     containerTag: number,
     callback: ?() => void,
     options: ?RenderRootOptions
@@ -7945,7 +7945,7 @@ export type ReactFabricType = {
     eventType: string
   ): void,
   render(
-    element: Element<ElementType>,
+    element: MixedElement,
     containerTag: number,
     callback: ?() => void,
     concurrentRoot: ?boolean,