chore: format batch_transaction_test.py with black (hiero-ledger#1520) (hiero-ledger#1606)

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

Author: Pradeepbeleri

CHANGELOG.md

@@ -8,6 +8,7 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 
 ### Tests
 - Format tests/unit/logger_test.py with black for code style consistency (#1541)
+- Format `tests/unit/batch_transaction_test.py` with Black.(`#1520`)
 - Style: formatted `tests/unit/prng_transaction_test.py` with black (#1546)
 - Formatted contract unit tests with black for consistent style. (#1523)
 - Format account test files with Black (#1519)