chore(aci): bump offset for fake IDs (#104051)

I'm a bit concerned that we have 500 million+ open periods already. Bump
the offset for fake IDs to 10 billion so there's a vastly reduced risk
of us running into it with real open period IDs.

Author: mifu67

src/sentry/incidents/endpoints/serializers/utils.py

@@ -1,4 +1,4 @@
-OFFSET = 10**9
+OFFSET = 10**10
 
 
 def get_fake_id_from_object_id(obj_id: int) -> int:

tests/sentry/incidents/serializers/test_workflow_engine_detector.py

@@ -5,6 +5,7 @@
 from django.core.cache import cache
 
 from sentry.api.serializers import serialize
+from sentry.incidents.endpoints.serializers.utils import OFFSET
 from sentry.incidents.endpoints.serializers.workflow_engine_detector import (
     WorkflowEngineDetectorSerializer,
 )
@@ -22,8 +23,6 @@
     TestWorkflowEngineSerializer,
 )
 
-OFFSET = 10**9
-
 
 class TestDetectorSerializer(TestWorkflowEngineSerializer):
     def setUp(self) -> None: