Add timeout for deleting closed incidents

[DiTsi]

Description
Implement automatic deletion of closed incidents after a configurable timeout.

Configuration format
incident

incident:
  timeouts:
    closed: 1y

Default value: 30d

Requirements

• File names of incidents must be renamed before deletion (to avoid overwriting if new incidents with the same parameters appear)
• Documentation must be updated to describe the new configuration option and its behavior

Feature should fix errors:

2025-08-08 19:16:01,086 ERROR Error handling queue item update_status: 'closed'
2025-08-08 19:16:01,188 ERROR Error handling queue item update_status: 'closed'