test-selection gap: run rspec foss-impact for spec/features/work_items/work_item_spec.rb

Context

We have identified a master-brokentest-selection-gap in #391609 (comment 1279375695):

We should probably fix the test gap as spec/features/work_items/work_item_spec.rb didn't run in the rspec foss-impact child pipeline.\

See the files that were detected as "related" to the changes made in the MR: https://gitlab.com/gitlab-org/gitlab/-/jobs/3765789337, spec/features/work_items/work_item_spec.rb isn't there.

Goal

Fix this test gap.