Move execution unit estimation to the very last part of tx building

Redeemer index will change during txbuilding. If execution unit estimation is performed before the final redeemer index is finalized, there could be mismatch between the index returned from estimation and the index stored locally in txbuilder.

Author: cffls

pycardano/txbuilder.py

@@ -865,9 +865,6 @@ def build(
         Returns:
             TransactionBody: A transaction body.
         """
-        self._update_execution_units(
-            change_address, merge_change, collateral_change_address
-        )
         self._ensure_no_input_exclusion_conflict()
         selected_utxos = []
         selected_amount = Value()
@@ -1000,6 +997,10 @@ def build(
 
         self._set_collateral_return(collateral_change_address or change_address)
 
+        self._update_execution_units(
+            change_address, merge_change, collateral_change_address
+        )
+
         self._add_change_and_fee(change_address, merge_change=merge_change)
 
         tx_body = self._build_tx_body()