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>

beacon_node/execution_layer/src/test_utils/mock_builder.rs

@@ -405,7 +405,7 @@ impl<E: EthSpec> mev_rs::BlindedBlockProvider for MockBuilder<E> {
         let payload_attributes = match fork {
             ForkName::Merge => PayloadAttributes::new(timestamp, *prev_randao, fee_recipient, None),
             // the withdrawals root is filled in by operations
-            ForkName::Capella | ForkName::Eip4844 => {
+            ForkName::Capella => {
                 PayloadAttributes::new(timestamp, *prev_randao, fee_recipient, Some(vec![]))
             }
             ForkName::Base | ForkName::Altair => {
@@ -452,7 +452,7 @@ impl<E: EthSpec> mev_rs::BlindedBlockProvider for MockBuilder<E> {
                 value: to_ssz_rs(&Uint256::from(DEFAULT_BUILDER_PAYLOAD_VALUE_WEI))?,
                 public_key: self.builder_sk.public_key(),
             }),
-            ForkName::Base | ForkName::Altair | ForkName::Eip4844 => {
+            ForkName::Base | ForkName::Altair => {
                 return Err(BlindedBlockProviderError::Custom(format!(
                     "Unsupported fork: {}",
                     fork