Make some specs compliant with Rails 7

What does this MR do and why?

It extracts multiple minor commits from the Rails 7 Upgrade MR: !90907 (commits)

• Fix nested travel_to
• Fix specs using anonymous ActiveRecord models
• Fix cycle analytics spec
• Fix ProjectMember validation spec
• Fix vulnerability_feedback_controller_spec by providing project
• Cast Settings to hash before calling deep_stringify_keys