fix: Fix address coin balances transformer (blockscout#11627)

apps/indexer/lib/indexer/transform/address_coin_balances.ex

@@ -18,11 +18,7 @@ defmodule Indexer.Transform.AddressCoinBalances do
   end
 
   defp reducer({:blocks_params, blocks_params}, acc) when is_list(blocks_params) do
-    # a block MUST have a miner_hash and number
-    Enum.into(blocks_params, acc, fn %{miner_hash: address_hash, number: block_number}
-                                     when is_binary(address_hash) and is_integer(block_number) ->
-      %{address_hash: address_hash, block_number: block_number}
-    end)
+    Enum.reduce(blocks_params, acc, &blocks_params_reducer/2)
   end
 
   defp reducer({:internal_transactions_params, internal_transactions_params}, initial)
@@ -65,6 +61,13 @@ defmodule Indexer.Transform.AddressCoinBalances do
     end)
   end
 
+  defp blocks_params_reducer(%{miner_hash: address_hash, number: block_number}, acc)
+       when is_binary(address_hash) and is_integer(block_number) do
+    MapSet.put(acc, %{address_hash: address_hash, block_number: block_number})
+  end
+
+  defp blocks_params_reducer(_block_params, acc), do: acc
+
   defp internal_transactions_params_reducer(%{block_number: block_number} = internal_transaction_params, acc)
        when is_integer(block_number) do
     case internal_transaction_params do