processPendingDeposits can jump as high as 1.2s on epoch transitions

[philknows]

Describe the bug

~~Since fulu~~, processPendingDeposits can take up to 1.2s during epoch transitions more frequently and at a higher cost in processing time than Electra.

Expected behavior

We need to minimize overhead cost and frequency of these spikes to at least Electra levels or better.

Steps to reproduce

No response

Additional context

No response

Operating system

Linux

Lodestar version or commit hash

v1.35.0-rc.1

[twoeths]

this is not fulu specific, it happens pre-fulu as well

since this happens randomly, it's very likely it's the result of building a new tree (with slice() api) then it triggered gc this is the same situation to processRewardsAndPenalties