Fix layout for "There are other correct answers." checkbox

[PhilippImhof]

Currently, the checkbox "There are other correct answers." is too close to the input field for model answers. This is due to some style tweaking done by core's multichoice question.

This PR "overrides the override" and brings back the normal layout.

[coveralls]

Pull Request Test Coverage Report for Build 15236655826

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.4%) to 96.847%

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Totals
Change from base Build 15236321570:	-0.4%
Covered Lines:	4055
Relevant Lines:	4187

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💛 - Coveralls

[PhilippImhof]

Waiting to see what happens in MDL-85240 before merging this one.

[PhilippImhof]

MDL-85240 has been merged to the main branch, i. e. it will be included in Moodle 5.1 and later only. Therefore, it makes sense to merge this PR and keep the workaround for some years at least.