[KSPM] Leader has a memory leak

[amirbenun]

Background

On our environments we have seen that after a few cycles the leader crashes because it is out of memory.
This only happens to the leader, only in the EKS benchmark.
Elastic Agent version: 8.15.1 (with 8.14.3 it didn't happen).

The agent logs indicate OOM
The agent metrics during the leading period

Definition of done

• Understand the cause of the leak

Issues

• Related: [KSPM] Increase the leader election lease duration #2578