Run process_builder_pending_payments before effective balance updates (#4737)

Long form reasoning on this change in the discord
[chat](https://discord.com/channels/595666850260713488/874767108809031740/1436395151655305389)

TLDR:
Move `process_builder_pending_payments` to run before
`process_effective_balance_updates` in `process_epoch`. This makes
`compute_exit_epoch_and_update_churn` use the current epoch effective
balances, matching `process_execution_payload` behavior and avoiding
inconsistent updates to `state.exit_balance_to_consume` and
`state.earliest_exit_epoch`

Author: shane-moore

specs/gloas/beacon-chain.md

@@ -684,15 +684,15 @@ def process_epoch(state: BeaconState) -> None:
     process_eth1_data_reset(state)
     process_pending_deposits(state)
     process_pending_consolidations(state)
+    # [New in Gloas:EIP7732]
+    process_builder_pending_payments(state)
     process_effective_balance_updates(state)
     process_slashings_reset(state)
     process_randao_mixes_reset(state)
     process_historical_summaries_update(state)
     process_participation_flag_updates(state)
     process_sync_committee_updates(state)
     process_proposer_lookahead(state)
-    # [New in Gloas:EIP7732]
-    process_builder_pending_payments(state)
 ```
 
 #### New `process_builder_pending_payments`