Allow #traits_for_enum to be used in a FactoryBot factory without a block

[harrylewis]

This PR fixes a bug that arose in relation to FactoryBot's recent 6.0.0 version release. This release introduced a new method, #traits_for_enum, which can be used to dynamically define factory traits for an enumerated attribute.

The behaviour expected is that usage of this method (which does not take a block argument) does not produce a FactoryBot/AttributeDefinedStatically offense.

The actual behaviour is that it does produce this offense because it is assumed to be an attribute, which should be defined with a block. The fix is simply to add it to the list of pre-qualified methods.

The documentation surrounding this cop does not make any mention around what methods are allowed to be used without a block, so I didn't feel it was necessary to update the documentation.

I believe this constitutes a "user-observable" change, but am not sure. If you feel it does, I will add a commit to add an entry to the CHANGELOG.md.

This fixes #943.

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Before submitting the PR make sure the following are checked:

• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Updated documentation.
• Added an entry to the CHANGELOG.md if the new code introduces user-observable changes.
• The build (bundle exec rake) passes (be sure to run this locally, since it may produce updated documentation that you will need to commit).

[harrylewis]

Adding :traits_for_enum caused a Layout/LineLength offense, so I turned the horizontal list into a vertical list. I also alphabetized the list to align with what was done with the other constants below.

[harrylewis]

One of the non-required builds failed, edge-rubocop. It doesn't look like the failure has anything to do with my changes. Given it is testing using the "edge" of Rubocop, I'm assuming it is susceptible to failures like this. Let me know if there is anything I can do to resurrect the failing test.

[pirj]

Thanks a lot!

[Darhazer]

You need to add s Changelog entry though

[harrylewis]

@Darhazer I added a CHANGELOG entry. I used the "Fix" verb because the bug label was applied to the original issue.

Also, regarding the checklist item "squashed related commits together", I'm not sure if it means to squash all commits in the branch into one, or if it is good enough to make sure the PR is merged into master with a squash commit. Happy to do either!

[harrylewis]

I didn't realize at first what was required to fill out a CHANGELOG entry. I really appreciate the accompanying tests though. They helped me understand was was required!