[chore] switch to timezone.utc instead of utcnow() since the last one is deprecated in Python 12 (#3539)

Author: ssenchenko

integration/helpers/deployer/deployer.py

@@ -29,7 +29,7 @@
 import sys
 import time
 from collections import OrderedDict
-from datetime import datetime
+from datetime import datetime, timezone
 
 import botocore
 
@@ -140,7 +140,7 @@ def create_changeset(
             "ChangeSetType": changeset_type,
             "Parameters": parameter_values,
             "Capabilities": capabilities,
-            "Description": f"Created by SAM CLI at {datetime.utcnow().isoformat()} UTC",
+            "Description": f"Created by SAM CLI at {datetime.now(timezone.utc).isoformat()} UTC",
             "Tags": tags,
         }
 

integration/helpers/deployer/utils/time_util.py

@@ -122,7 +122,7 @@ def parse_date(date_string):
         # will use current local time as the base for subtraction, but falsely assume it is a UTC time. Therefore
         # the time that dateparser returns will be a `datetime` object that did not have any timezone information.
         # So be explicit to set the time to UTC.
-        "RELATIVE_BASE": datetime.datetime.utcnow()
+        "RELATIVE_BASE": datetime.datetime.now(datetime.timezone.utc)
     }
 
     return dateparser.parse(date_string, settings=parser_settings)