gomod: update zoekt

Created by: keegancsmith

Includes the following changes:

• https://github.com/sourcegraph/zoekt/commit/fe739e1 indexserver: debug list support -exclude_indexed
• https://github.com/sourcegraph/zoekt/commit/204b687 indexeserver: better logging for sourcegraphClient
• https://github.com/sourcegraph/zoekt/commit/3e8cba3 dockerfile: include curl
• https://github.com/sourcegraph/zoekt/commit/8a49c63 indexserver: seperate tmpfriend for debug vs main command
• https://github.com/sourcegraph/zoekt/commit/a118209 indexserver: minor refactors around fetch
• https://github.com/sourcegraph/zoekt/commit/8efa934 ci: add shfmt

Test Plan: CI