[6.x] Fix chunked queries not honoring user-defined limits and offsets

[duncanmcclean]

This pull request fixes an issue where the ->chunk() method on our query builder ignores any user-defined limits and offsets.

This meant that the following query would give you 10 chunks of 5 entries, rather than 2 chunks of 5 entries:

use Statamic\Facades\Entry;

Entry::query()
  ->where('collection', 'playground')
  ->limit(10)
  ->chunk(5, function ($entries) {
    dump($entries);
  });

This was fixed in Laravel 12, so I've copied over the fix (and the related test cases) in this PR. The Laravel PR has more context around the issue, and the fix.

Since this introduces a change in behaviour, this pull request is targeting the master branch.

Fixes #11698.