Remove gitlab-foss reviewer

GitLab EE and CE were merged into
a single repo, nobody reviews MRs in
the FOSS repo.

doc/development/go_guide/index.md

@@ -63,7 +63,6 @@ file and ask your manager to review and merge.
 ```yaml
 projects:
   gitlab: reviewer go
-  gitlab-foss: reviewer go
 ```
 
 ## Code style and format