Simplify Sorting Logic

specs/_features/eip7251/fork.md

@@ -128,21 +128,16 @@ def upgrade_to_eip7251(pre: deneb.BeaconState) -> BeaconState:
         pending_consolidations=[],
     )
 
-    activation_queue = []
-    pre_activation_queue = []
-    below_minimum = []
-    for index, validator in enumerate(post.validators):
-        if validator.activation_epoch == FAR_FUTURE_EPOCH:
-            if validator.activation_eligibility_epoch != FAR_FUTURE_EPOCH:
-                activation_queue.append(index)
-            else:
-                if validator.effective_balance >= MIN_ACTIVATION_BALANCE:
-                    pre_activation_queue.append(index)
-                else:
-                    below_minimum.append(index)
-
-    activation_queue.sort(key=lambda index: (post.validators[index].activation_eligibility_epoch, index))
-    for index in activation_queue + pre_activation_queue + below_minimum:
+    # add validators that are not yet active to pending balance deposits
+    pre_activation = sorted([
+        index for index, validator in enumerate(post.validators)
+        if validator.activation_epoch == FAR_FUTURE_EPOCH
+    ], key=lambda index: (
+        post.validators[index].activation_eligibility_epoch,
+        post.validators[index].effective_balance < MIN_ACTIVATION_BALANCE,
+        index
+    ))
+    for index in pre_activation:
         queue_entire_balance_and_reset_validator(post, ValidatorIndex(index))
 
     # Ensure early adopters of compounding credentials go through the activation churn