gomod: zoekt does periodic config invalidation
Created by: keegancsmith
This is to help prevent us failing to notice a repo has updated in case of an infrastructure failure.
- https://github.com/sourcegraph/zoekt/commit/c8a2f8c indexserver: scale configFingerprint reset time relative to corpus
- https://github.com/sourcegraph/zoekt/commit/5f722e5 indexserver: use batching in ForceIterateIndexOptions
- https://github.com/sourcegraph/zoekt/commit/e77e7bc indexserver: invadildate config fingerprint every ~15min