Replace deprecated datetime.utcnow()

The datetime.utcnow() is deprecated in Python 3.12.
Replace datetime.utcnow() with oslo_utils.timeutils.utcnow().
This bumps oslo.utils to 7.0.0.

Change-Id: Icccbb0549add686a744a72b354932471cbf91c92
Signed-off-by: Takashi Natsume <takanattie@gmail.com>

watcher/decision_engine/datasources/ceilometer.py

@@ -158,7 +158,7 @@ class CeilometerHelper(base.DataSourceBase):
     def statistic_aggregation(self, resource=None, resource_type=None,
                               meter_name=None, period=300, granularity=300,
                               aggregate='mean'):
-        end_time = datetime.datetime.utcnow()
+        end_time = timeutils.utcnow()
         start_time = end_time - datetime.timedelta(seconds=int(period))
 
         meter = self._get_meter(meter_name)

watcher/decision_engine/datasources/gnocchi.py

@@ -16,12 +16,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from datetime import datetime
 from datetime import timedelta
 
 from gnocchiclient import exceptions as gnc_exc
 from oslo_config import cfg
 from oslo_log import log
+from oslo_utils import timeutils
 
 from watcher.common import clients
 from watcher.decision_engine.datasources import base
@@ -69,7 +69,7 @@ class GnocchiHelper(base.DataSourceBase):
     def statistic_aggregation(self, resource=None, resource_type=None,
                               meter_name=None, period=300, aggregate='mean',
                               granularity=300):
-        stop_time = datetime.utcnow()
+        stop_time = timeutils.utcnow()
         start_time = stop_time - timedelta(seconds=(int(period)))
 
         meter = self._get_meter(meter_name)

watcher/decision_engine/datasources/monasca.py

@@ -19,6 +19,7 @@
 import datetime
 
 from monascaclient import exc
+from oslo_utils import timeutils
 
 from watcher.common import clients
 from watcher.decision_engine.datasources import base
@@ -58,8 +59,7 @@ class MonascaHelper(base.DataSourceBase):
             period = int(datetime.timedelta(hours=3).total_seconds())
         if not start_time:
             start_time = (
-                datetime.datetime.utcnow() -
-                datetime.timedelta(seconds=period))
+                timeutils.utcnow() - datetime.timedelta(seconds=period))
 
         start_timestamp = None if not start_time else start_time.isoformat()
         end_timestamp = None if not end_time else end_time.isoformat()
@@ -86,7 +86,7 @@ class MonascaHelper(base.DataSourceBase):
     def statistic_aggregation(self, resource=None, resource_type=None,
                               meter_name=None, period=300, aggregate='mean',
                               granularity=300):
-        stop_time = datetime.datetime.utcnow()
+        stop_time = timeutils.utcnow()
         start_time = stop_time - datetime.timedelta(seconds=(int(period)))
 
         meter = self._get_meter(meter_name)