fix: taa rough timestamp timezone from datetime

Fixes #2553

Signed-off-by: Daniel Bluhm <dbluhm@pm.me>

aries_cloudagent/ledger/indy_vdr.py

@@ -8,7 +8,7 @@
 import os.path
 import tempfile
 
-from datetime import datetime, date
+from datetime import datetime, date, timezone
 from io import StringIO
 from pathlib import Path
 from time import time
@@ -923,7 +923,7 @@ def taa_rough_timestamp(self) -> int:
         """
         return int(
             datetime.combine(
-                date.today(), datetime.min.time(), datetime.timezone.utc
+                date.today(), datetime.min.time(), timezone.utc
             ).timestamp()
         )