SIENTIAPDE-1974

SIENTIAPDE-1974 Fix Sonar issues: reduce gather_read_tags complexity, import pytest as module

Move the per-pipeline read tag loop of gather_read_tags into
_add_pipeline_read_tags (cognitive complexity 16 -> ~6) and import pytest
as a module in test_mongo_db.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/orchestrator/activities/test_mongo_db.py

@@ -1,14 +1,14 @@
 from datetime import UTC, datetime
 from unittest.mock import ANY, AsyncMock, MagicMock, call, patch
 
-from pytest import fixture, mark, raises
+import pytest
 from sientia_do.notifications.models import NotificationLevel
 from sientia_do.temporal.constants import DATETIME_FORMAT_MS_WITH_TZ
 
 from orchestrator.activities.mongo_db import MongoDB
 
 
-@fixture
+@pytest.fixture
 @patch('orchestrator.activities.mongo_db.MongoDBRepository')
 def mongo_db(mongo_mock):
     mongo = MongoDB(
@@ -294,7 +294,7 @@ def test_update_pipelines_timestamps_success(now_mock, mongo_db):
 
 
 @patch('orchestrator.activities.mongo_db.now')
-@mark.parametrize(
+@pytest.mark.parametrize(
     'pipelines', [[], [{'schedule_name': 'test1', 'namespace': 'test1', 'success': False}]]
 )
 def test_update_pipelines_timestamps_all_failed_stamps_nothing(now_mock, mongo_db, pipelines):
@@ -373,7 +373,7 @@ def test_update_pipelines_timestamps_failures_notified_together(now_mock, mongo_
         Exception('timeout'),
     ]
 
-    with raises(RuntimeError, match='Failed to update 2 of 3 pipelines timestamps'):
+    with pytest.raises(RuntimeError, match='Failed to update 2 of 3 pipelines timestamps'):
         mongo_db.update_pipelines_timestamps(input_data)
 
     assert mongo_db.mongo_db_repository.update_one.call_count == 3
@@ -462,7 +462,7 @@ def test_delete_pipelines_timestamps_success(now_mock, mongo_db):
     )
 
 
-@mark.parametrize(
+@pytest.mark.parametrize(
     'pipelines', [[], [{'schedule_name': 'test1', 'namespace': 'test1', 'success': False}]]
 )
 def test_delete_pipelines_timestamps_all_failed_deletes_nothing(mongo_db, pipelines):