Merge branch 'break-up-redundant-cancellation-into-methods' into 'master'

Add new helper method to CancelRedundantPipelineService

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/168711



Merged-by: Jarka Košanová <jarka@gitlab.com>
Approved-by: Furkan Ayhan <furkanayhn@gmail.com>
Approved-by: Jarka Košanová <jarka@gitlab.com>
Reviewed-by: Jarka Košanová <jarka@gitlab.com>
Co-authored-by: drew <dscimino@gmail.com>