Create routing table for `ci_pipelines`

Problem

We need to partition ci_pipelines in order to stop the growth of this table.

Solution

• Create async constraint for gitlab.com
• Add constraint for self-managed
• Create p_ci_pipelines

https://docs.gitlab.com/ee/development/database/table_partitioning.html#step-6---create-parent-table-and-attach-existing-table-as-the-initial-partition