Auto-correct remaining offenses for Performance/StringInclude

What does this MR do and why?

This MR fixes all remaining offenses for 👮 Performance/StringInclude via:

bundle execrubocop -A --only Performance/StringInclude app/models/snippet_repository.rb config/initializers/macos.rb config/spring.rb ee/app/models/ee/container_registry/event.rb ee/lib/gitlab/auth/smartcard/certificate.rb lib/kramdown/parser/atlassian_document_format.rb lib/prometheus/pid_provider.rb spec/features/projects/jobs_spec.rb spec/spec_helper.rb

The TODO YAML is now empty has been removed.

Contributes to #239356

⚠ Safety

Because auto-correction in not safe for =~ we use &.include? where the receiver is potentially nil.

How to set up and validate locally

bin/rake rubocop:todo:generate[Performance/StringInclude]

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.