Adding ci_pipelines to LFK config file

What does this MR do and why?

Adding ci_pipelines to LFK config file

Addressing: #505813 (closed)

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

How to set up and validate locally

On master:

[3] pry(main)> Gitlab::Database::LooseForeignKeys.definitions_by_table.keys.grep /pipelines/
=> ["p_ci_pipelines"]

On this branch

Gitlab::Database::LooseForeignKeys.definitions_by_table.keys.grep /pipelines/
=> ["ci_pipelines", "p_ci_pipelines"]

This list of tables is used here: https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/services/loose_foreign_keys/process_deleted_records_service.rb#L15

Related to #505813 (closed)