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>

validator_client/src/signing_method/web3signer.rs

@@ -27,7 +27,6 @@ pub enum ForkName {
     Altair,
     Bellatrix,
     Capella,
-    Eip4844,
 }
 
 #[derive(Debug, PartialEq, Serialize)]
@@ -97,11 +96,6 @@ impl<'a, T: EthSpec, Payload: AbstractExecPayload<T>> Web3SignerObject<'a, T, Pa
                 block: None,
                 block_header: Some(block.block_header()),
             }),
-            BeaconBlock::Eip4844(_) => Ok(Web3SignerObject::BeaconBlock {
-                version: ForkName::Eip4844,
-                block: None,
-                block_header: Some(block.block_header()),
-            }),
         }
     }