Merge pull request #3542 from etan-status/df-nodomain

Remove unused `DOMAIN_BLOB_SIDECAR`

specs/deneb/beacon-chain.md

@@ -11,7 +11,6 @@
 - [Introduction](#introduction)
 - [Custom types](#custom-types)
 - [Constants](#constants)
-  - [Domain types](#domain-types)
   - [Blob](#blob)
 - [Preset](#preset)
   - [Execution](#execution)
@@ -67,12 +66,6 @@ Deneb is a consensus-layer upgrade containing a number of features. Including:
 
 ## Constants
 
-### Domain types
-
-| Name | Value |
-| - | - |
-| `DOMAIN_BLOB_SIDECAR` | `DomainType('0x0B000000')` |
-
 ### Blob
 
 | Name | Value |