DOC: fix EX03 Errors for pandas.read_json
- [X] Ref: https://github.com/pandas-dev/pandas/issues/56804

Fix these EX03 Errors for `pandas.read_json`
```
flake8 error: line 6, col 23: F821 undefined name '_'
flake8 error: line 8, col 23: F821 undefined name '_'
flake8 error: line 10, col 23: F821 undefined name '_'
```
The CI wasn't working to validate those docstrings. It's now been fixed, and there are some errors here and in your other PR, can you have a look please? > The CI wasn't working to validate those docstrings. It's now been fixed, and there are some errors here and in your other PR, can you have a look please?

I am actually confused about why it still errored out when commented with `  # doctest: +SKIP` and `  # noqa: E501` (also in another PR). I will dig into when I have more spare time. Closed by https://github.com/pandas-dev/pandas/pull/57025