Fix cop FactoryBot/InlineAssociation offenses for CA group stages

What does this MR do?

Contributes to #267606 (closed).

This MR also "unexcludes" two files to be picked by FactoryBot/InlineAssociation 😅

Does this MR meet the acceptance criteria?

Conformity

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  • I have not included a changelog entry because it's a developer-facing change.
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