Remove "expiry" from known_events

What does this MR do and why?

This is the first MR to simplify known_events files. It removed expiry option as it's not used (only default values are set).

Events key arent affected (default value continue to be used explicitly now) so Redis dada migration is not needed.

Screenshots or screen recordings

No UI affected

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

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.

Related to #387783 (closed)