SIENTIAPDE-1193

Update requirements and refactor datetime handling in OpcManager for timezone support

- Commented out the specific version of sientia-dataops-library in requirements.txt and added a local path.
- Updated GITHUB_BRANCH in values.yaml for consistency with current development.
- Refactored source_timestamp handling in OpcManager to include timezone information.
- Adjusted timestamp formatting in test cases to reflect the new datetime format with timezone.

tests/unit/managers/test_opc_manager.py

@@ -394,7 +394,7 @@ def test_datachange_notification(metrics, opc_manager_subscribed):
         {
             "tag": "ns=3;i=1001",
             "name": "Counter",
-            "timestamp": "2021-01-01 00:00:00",
+            "timestamp": "2021-01-01 00:00:00-0300",
             "value": 42,
         },
     )
@@ -403,7 +403,7 @@ def test_datachange_notification(metrics, opc_manager_subscribed):
         {
             "tag": "ns=3;i=1001",
             "name": "Counter",
-            "timestamp": "2021-01-01 00:00:00",
+            "timestamp": "2021-01-01 00:00:00-0300",
             "value": 42,
         },
     )