Use get_list_select_related (fix #1493)

[mpasternak]

Problem

To be honest, this is not exactly a problem, as long as you don't heavily modify Django admin and write classes inheriting from ExportMixin. Since some time Django has a special utility function for getting list_select_related, which is called get_list_select_related and it should be used to override some settings.

In my application I used it to implement dynamic Django admin columns (https://github.com/iplweb/bpp/blob/dev/src/dynamic_columns/mixins.py#L8) and it occurred, that ExportMixin (that I also use, that's a quite big project) doesn't play nicely with it, so well, here I am.

Solution

All this needs is to analogically call to get_*, just like we already do in get_list_display and such.

Acceptance Criteria

No additional tests, Django 3.2 and 4.0 pass.

Screenshots of my changes... are identical to the changes.

I documented the changes in the changelog.rst and added myself to the deep bottom of AUTHORS.

[coveralls]

Coverage remained the same at 100.0% when pulling 5f01347 on mpasternak:main into 2255245 on django-import-export:main.

[matthewhegarty]

thank you 👍