Remove todo! lines from gloas (#8383)

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -5792,7 +5792,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                     execution_payload_value,
                 )
             }
-            BeaconState::Gloas(_) => todo!("Gloas block production"),
+            BeaconState::Gloas(_) => return Err(BlockProductionError::GloasNotImplemented),
         };
 
         let block = SignedBeaconBlock::from_block(

beacon_node/beacon_chain/src/errors.rs

@@ -319,6 +319,8 @@ pub enum BlockProductionError {
     FailedToBuildBlobSidecars(String),
     MissingExecutionRequests,
     SszTypesError(ssz_types::Error),
+    // TODO(gloas): Remove this once Gloas is implemented
+    GloasNotImplemented,
 }
 
 easy_from_to!(BlockProcessingError, BlockProductionError);