chore: investigate and fix flaky e2e tests

[weboko]

Description

In CI we have following test being flaky:

  1) Peer Cache Discovery
       should discover peers from provided peer cache:

      AssertionError: expected 3 to equal 2
      + expected - actual

      -3
      +2
      
      at Context.<anonymous> (file:///home/runner/work/js-waku/js-waku/packages/tests/tests/peer-cache/peer_cache.spec.ts:78:42)
      at processTicksAndRejections (node:internal/process/task_queues:105:5)