chore: Mark UTFSequence as deprecated to remove in the future

Summary:
if you check the search results you won't find any usages of `UTFSequence` module. Also it wasn't documented.

So, it can be treated as dead-code and need to be removed from RN package

```bash
open https://github.com/search?q=%22UTFSequence.BOM%22&type=code
open https://github.com/search?q=%22UTFSequence.BULLET%22&type=code
open https://github.com/search?q=%22UTFSequence.BULLET_SP%22&type=code
open https://github.com/search?q=%22UTFSequence.MIDDOT%22&type=code
open https://github.com/search?q=%22UTFSequence.MIDDOT_SP%22&type=code
open https://github.com/search?q=%22UTFSequence.MIDDOT_KATAKANA%22&type=code
open https://github.com/search?q=%22UTFSequence.MDASH%22&type=code
open https://github.com/search?q=%22UTFSequence.MDASH_SP%22&type=code
open https://github.com/search?q=%22UTFSequence.NDASH%22&type=code
open https://github.com/search?q=%22UTFSequence.NDASH_SP%22&type=code
open https://github.com/search?q=%22UTFSequence.NEWLINE%22&type=code
open https://github.com/search?q=%22UTFSequence.NBSP%22&type=code
open https://github.com/search?q=%22UTFSequence.PIZZA%22&type=code
open https://github.com/search?q=%22UTFSequence.TRIANGLE_LEFT%22&type=code
open https://github.com/search?q=%22UTFSequence.TRIANGLE_RIGHT%22&type=code
```
In RN repo in used in one places and can be replaced with string litaral:  https://github.com/facebook/react-native/blob/8bcfb3ba1c16b1ba45058798bf43ecdc9bd42d3a/packages/react-native/Libraries/LogBox/Data/parseLogBoxLog.js#L109

## Changelog:

[GENERAL] [DEPRECATED] - Mark undocumented `UTFSequence` module as deprecated

X-link: #57122

Reviewed By: zeyap

Differential Revision: D108005122

Pulled By: javache

fbshipit-source-id: 0641b1cd90cc9c4924a4afb3779a94b58e7153d4

Author: retyui

packages/react-native/index.js

@@ -368,6 +368,10 @@ module.exports = {
     return require('./Libraries/Utilities/useWindowDimensions').default;
   },
   get UTFSequence() {
+    warnOnce(
+      'utfsequence-will-be-remove',
+      'UTFSequence will be removed in a future release.',
+    );
     return require('./Libraries/UTFSequence').default;
   },
   get Vibration() {