Read data from p_ci_job_artifacts

Problem

After the routing table is created, we must change the table_name in the model to use the routing table instead of the partition.

Solution

Incremental rollout of reading from p_ci_job_artifacts, similar to #439069 (closed).

1. Use our Partitionable::Switch strategy, !144709 (merged)

• https://docs.gitlab.com/ee/development/database/partitioning/list.html#step-9---analyze-the-partitioned-table-and-create-new-partitions
• https://docs.gitlab.com/ee/development/database/partitioning/list.html#step-10---update-the-application-to-use-the-partitioned-table