Bug: Delayed Indices Update Execution Due to Non-Deterministic Slot Ticker

[olegshmuelov]

Each handler is triggered by the slot ticker independently.
The CommitteeHandler relies on the data from the AttesterHandler and SyncCommitteeHandler to fetch and execute duties.
When the indicesChange signal is triggered, the attester and sync committee stores need to update their duties to reflect the latest state.

Due to the non-deterministic nature of the slot ticker, we encounter inconsistent behavior. Sometimes the indicesChange event is handled and executed within a single slot, while in other scenarios, it spans two slots, leading to potential race conditions and incorrect duty execution.

Problematic Scenario (Observed Behavior):

1. Slot 1:
   AttesterHandler receives the indicesChange trigger:
2. Slot 2:
   CommitteeHandler gets a ticker event and executes duties (based on outdated indices).
   AttesterHandler gets a ticker event and updates duties due to the indicesChange trigger.
3. Slot 3:
   CommitteeHandler executes duties, this time with updated indices, causing late duty execution for the indices change validators