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/fork_choice/src/fork_choice.rs

@@ -857,10 +857,7 @@ where
                     (parent_justified, parent_finalized)
                 } else {
                     let justification_and_finalization_state = match block {
-                        // TODO(eip4844): Ensure that the final specification
-                        // does not substantially modify per epoch processing.
-                        BeaconBlockRef::Eip4844(_)
-                        | BeaconBlockRef::Capella(_)
+                        BeaconBlockRef::Capella(_)
                         | BeaconBlockRef::Merge(_)
                         | BeaconBlockRef::Altair(_) => {
                             let participation_cache =