Error Tracking: Remove unused ActiveRecordStrategy

What does this MR do and why?

Error Tracking with the Postgres backend was disabled in #353639 (closed) (%14.9).

This MR removes parts of unused backend and contributes to #414933.

This MR refactor error tracking service specs to match the new default strategy.

Also, from now on, the refactored services run in random order.

Follow-up of !123139 (merged)

MR navigation

• Error Tracking: Remove ingestion API (!123139 - merged)
• Error Tracking: Remove unused collector utilities (!123191 - merged)
• Error Tracking: Remove unused ActiveRecordStrategy

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.