request()->merge(...) does not work any more after `v9.36.4`  update

- Laravel Version: 9.36.4
- PHP Version: 8.1.11
- Database Driver & Version: MySQL 8.1

### Description:
After update to 9.36.4 `request()->merge(...)` stopped working and does not replace the input.

### Steps To Reproduce:
Use the `request()->merge(['a' => 'c'])` on the json request which has `{"a": "b"}` in the request body.
