Stop creating issues if the instance is trimmed

Summary:
While working on D61398769, I saw that we are sometimes creating issues without a corresponding issue instance in cases where the instance is trimmed from the graph.

This diff fixes that by making sure to remove the associated issue when an issue instance is trimmed.

Reviewed By: yuhshin-oss

Differential Revision: D61410591

fbshipit-source-id: 17e1170d5f7c67d6622b8929bdd8c4def8fabf9a

sapp/trimmed_trace_graph.py

@@ -193,6 +193,7 @@ def _remove_instance(self, instance: IssueInstance) -> None:
         associations too"""
         instance_id = instance.id.local_id
         self._issue_instances.pop(instance_id, None)
+        self._issues.pop(instance.issue_id.local_id, None)
         for initial_frame_id in self._issue_instance_trace_frame_assoc[instance_id]:
             # initial frames are only associated with one issue
             self._trace_frame_issue_instance_assoc.pop(initial_frame_id, None)