Move delayed deletion cronjob settings to CE

What does this MR do and why?

This MR moves the cronjob configurations for delayed deletion to CE. This was missed as part of the down tier for deletayed deletion.

References

Screenshots or screen recordings

Before	After

How to set up and validate locally

Ensure that the cronjobs are configured when running in FOSS mode

▶ FOSS_ONLY=1 rails c
--------------------------------------------------------------------------------
 Ruby:         ruby 3.3.9 (2025-07-24 revision f5c772fc7c) [x86_64-linux]
 GitLab:       18.4.0-pre (4d0ab07f056) FOSS
 GitLab Shell: 14.44.0
 PostgreSQL:   16.8
-------------------------------------------------------------[ booted in 8.24s ]
Loading development environment (Rails 7.1.5.1)
[1] pry(main)> puts "EE enabled: #{Gitlab.ee?}"
EE enabled: false
=> nil
[2] pry(main)> Sidekiq::Cron::Job.all.select { |j| j.name.include?('adjourned') }.map(&:name)
=> ["adjourned_projects_deletion_cron_worker", "adjourned_group_deletion_worker"]
[3] pry(main)>

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Related to #565015 (closed)