Convert `p_ci_builds.upstream_pipeline_id` to bigint

Problem

This column references the ci_pipelines table and its column type is not bigint.

Process

Following the process outlined here, we must:

Step	MR	Workflow Status	Milestone
Initialize the conversion and ignore column	!129332 (merged)	workflowin dev	%16.2
Confirm backfill is finished and Async Create index			%16.3
Sync Create index and add foreign key constraint			%16.3
Swap the columns			%16.3
Remove the trigger and old integer columns			%16.4
Remove ignore rules			%16.5