Animated: Delete AnimatedNode.prototype.toJSON (#46382)

Summary:
Pull Request resolved: #46382

Deletes the `AnimatedNode.prototype.toJSON` method.

It was originally introduced by [#7442](#7442) as a means to resolve [#7441](#7441), where an error occurs attempting to serialize `AnimatedNode` instances.

However, this is no longer needed for that purpose because our inspector implementation is now more resilient. (It correctly reports the current style value instead of the `AnimatedNode` instance.)

The impetus for this change is that this `toJSON` method prevents a future performance optimization for all `Animated` components.

Changelog:
[General][Changed] - AnimatedNode (and its subclasses) no longer implement `toJSON()`.

Reviewed By: javache

Differential Revision: D62350726

fbshipit-source-id: c68edc98878e58d48bc677c4f1299bb1bd15c9c4

packages/react-native/Libraries/Animated/__tests__/Animated-test.js

@@ -162,10 +162,6 @@ describe('Animated tests', () => {
       expect(anim.__getValue()).toBe(15);
     });
 
-    it('convert to JSON', () => {
-      expect(JSON.stringify(new Animated.Value(10))).toBe('10');
-    });
-
     it('bypasses `setNativeProps` in test environments', async () => {
       const opacity = new Animated.Value(0);
 

packages/react-native/Libraries/Animated/nodes/AnimatedNode.js

@@ -182,10 +182,6 @@ export default class AnimatedNode {
     );
   }
 
-  toJSON(): any {
-    return this.__getValue();
-  }
-
   __getPlatformConfig(): ?PlatformConfig {
     return this._platformConfig;
   }

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

@@ -923,7 +923,6 @@ exports[`public API should not change unintentionally Libraries/Animated/nodes/A
   __callListeners(value: number): void;
   __getNativeTag(): number;
   __getNativeConfig(): Object;
-  toJSON(): any;
   __getPlatformConfig(): ?PlatformConfig;
   __setPlatformConfig(platformConfig: ?PlatformConfig): void;
 }