feat: Add Django 4.2 admin support

[fsbraun]

Django admin styles have changed. This fixes the delete-link styling and the readonly-fields styling

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (ae6ec18) 100.00% compared to head (9c7ba4b) 100.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #500 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 2 2 Lines 33 33 Branches 3 3 ========================================= Hits 33 33 ```

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[DmytroLitvinov]

Hi @fsbraun , Seems like that Pull Request can fix issue we have at our stage server when we upgraded to Django@4.2 and we have read-only fields.

I will look into details and let you know if it fixes so we can merge and release new version of djangocms-admin-style

[DmytroLitvinov]

@fsbraun , should it looks like that way?

[fsbraun]

@DmytroLitvinov IMHO it should look like a form with editable fields, but the inputs replaced by the fields' values. Would you expect something else?

[DmytroLitvinov]

For me it is fine that it looks like that way.

Also attaching how it looks for Django@4.2 without djangocms-admin-style

[fsbraun]

Yes, plain django admin style uses horizontal separation on large screens and vertical separation of label and field on small screens.

@vinitkumar OK for you, too? Can you review? 😎