chore: add PREVRANDAO as synonym for DIFFICULTY

Author: fselmo

packages/testing/src/execution_testing/client_clis/cli_types.py

@@ -216,6 +216,7 @@ def print(self) -> None:
 
 _opcode_synonyms = {
     "KECCAK256": "SHA3",
+    "DIFFICULTY": "PREVRANDAO",
 }