[BE] Optimize queries made to build the Assignee Cards

• Type: Task
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: None
• Fix Version/s: None
• Component/s: Workflow > Metrics
• Labels:
  • wf-technical-debt
• Epic Link: Workflow Technical Debts

Workflow Metrics assignee cards are getting slow when there are a large number of process and tasks(a few thousand)

Goals:

• Remove as much as possible the script metrics aim to reduce the query costs.
• Move script's logic to ingestion phase
• Run performance tests to verify and ensure improvements