Drop column ci_build_trace_sections.id column to address int4 overflow issue

The column ci_build_trace_sections.id is deemed to overflow it's int4 type soon (on GitLab.com). See #23924 (comment 220615965).

The proposal here is to simply drop the column and discuss how to do this most gracefully.

This should be done in 2 releases:

• Ignore the column with %12.4 -> !17805 (merged)
• Ship migration to drop the column with %12.5 -> !18741 (merged)
• Remove ignore column with %12.6

An POC MR for this change was created here and can be used as a reference !17499 (closed)