chore: format tests/unit/executable_test.py with black (hiero-ledger#1530) (hiero-ledger#1612)

Signed-off-by: Pradeepbeleri <pradpie@gmail.com>

Author: Pradeepbeleri

CHANGELOG.md

@@ -9,6 +9,7 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 
 
 ### Tests
+- Format `tests/unit/executable_test.py` with Black.(#1530)
 - Format `tests/unit/hedera_trust_manager_test.py` with Black for consistent code style (#1539)
 - Format tests/unit/logger_test.py with black for code style consistency (#1541)
 - Format `tests/unit/batch_transaction_test.py` with Black.(`#1520`)