Add auto_canceled_by_partition_id to p_ci_builds

What does this MR do and why?

We have an auto_canceled_by_id column on p_ci_builds which is a foreign key to ci_pipelines. Since p_ci_builds is partitioned and ci_pipelines will be partitioned next, we need to add the partitioning column to the foreign key. This MR adds the necessary column to the p_ci_builds table and backfills it with the current partition value.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #427882 (closed)