gomod: update zoekt
Created by: keegancsmith
- https://github.com/sourcegraph/zoekt/commit/7ad19f6 gitindex: respect flag -submodule
- https://github.com/sourcegraph/zoekt/commit/3c5cea3 indexserver: index new repos
- https://github.com/sourcegraph/zoekt/commit/8ea6c20 indexserver: create empty repos with proper ID
- https://github.com/sourcegraph/zoekt/commit/c5166c5 indexserver: do not bump unknown repos in queue
- https://github.com/sourcegraph/zoekt/commit/c08e204 indexserver: only try decode the returned repos
- https://github.com/sourcegraph/zoekt/commit/c94c451 indexserver: default config batch size of 10000
- https://github.com/sourcegraph/zoekt/commit/49086e3 shards: space out progress events