Fix Style/IfUnlessModifier offences

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What does this MR do and why?

Fixing offences for -

    - 'app/models/appearance.rb'
    - 'app/models/application_setting_implementation.rb'
    - 'app/models/bulk_imports/entity.rb'
    - 'app/models/ci/application_record.rb'
    - 'app/models/ci/build.rb'
    - 'app/models/ci/build_trace_chunk.rb'
    - 'app/models/ci/job_artifact.rb'
    - 'app/models/ci/pending_build.rb'
    - 'app/models/ci/pipeline.rb'
    - 'app/models/ci/runner.rb'

Related to #239356

.rubocop_todo/style/if_unless_modifier.yml

@@ -34,16 +34,6 @@ Style/IfUnlessModifier:
     - 'app/mailers/emails/members.rb'
     - 'app/mailers/emails/merge_requests.rb'
     - 'app/models/ability.rb'
-    - 'app/models/appearance.rb'
-    - 'app/models/application_setting_implementation.rb'
-    - 'app/models/bulk_imports/entity.rb'
-    - 'app/models/ci/application_record.rb'
-    - 'app/models/ci/build.rb'
-    - 'app/models/ci/build_trace_chunk.rb'
-    - 'app/models/ci/job_artifact.rb'
-    - 'app/models/ci/pending_build.rb'
-    - 'app/models/ci/pipeline.rb'
-    - 'app/models/ci/runner.rb'
     - 'app/models/concerns/ci/artifactable.rb'
     - 'app/models/concerns/deprecated_assignee.rb'
     - 'app/models/concerns/group_descendant.rb'