Clean capella (#4019)

## Issue Addressed

Cleans up all the remnants of 4844 in capella. This makes sure when 4844 is reviewed there is nothing we are missing because it got included here 

## Proposed Changes

drop a bomb on every 4844 thing 

## Additional Info

Merge process I did (locally) is as follows:
- squash merge to produce one commit
- in new branch off unstable with the squashed commit create a `git revert HEAD` commit
- merge that new branch onto 4844 with `--strategy ours`
- compare local 4844 to remote 4844 and make sure the diff is empty
- enjoy

Co-authored-by: Paul Hauner <paul@paulhauner.com>

consensus/state_processing/src/per_epoch_processing.rs

@@ -40,7 +40,7 @@ pub fn process_epoch<T: EthSpec>(
     match state {
         BeaconState::Base(_) => base::process_epoch(state, spec),
         BeaconState::Altair(_) | BeaconState::Merge(_) => altair::process_epoch(state, spec),
-        BeaconState::Capella(_) | BeaconState::Eip4844(_) => capella::process_epoch(state, spec),
+        BeaconState::Capella(_) => capella::process_epoch(state, spec),
     }
 }