Address the Primary Key Overflow risk for the ci_build_needs table - Step 3: Drop temporary columns and triggers

Instead of creating issues for each step, the work for the steps is outlined below. An MR will be created for each of the steps.

• Step 3.1: Drop trigger to keep columns in sync (14.3)
• Step 3.2: Drop the columns (14.3)
• Step 3.3: Remove the ignore rule (14.4)