search: disable integration test for structural search alerts
Created by: rvantonder
This is confirmed flake. I think it might be a combination of racing/priority for alerts (?). This test specifically is probably also better as a unit test/static test now.
Red in: https://buildkite.com/sourcegraph/sourcegraph/builds/153113#018144cb-c641-4005-b816-c100039fb466
Green in commit after: https://buildkite.com/sourcegraph/sourcegraph/builds/153117
Test plan
Remove flake.
