Grant VPT github group admin access

We have a GitHub group called `tools/vox-pupuli-tasks`. They should have
admin access to voxpupu.li.

https://github.com/orgs/voxpupuli/teams/tools-vox-pupuli-tasks/members

(I'm not sure if the slug is tools-vox-pupuli-tasks or
tools/vox-pupuli-tasks).

Author: bastelfreak

config/voxpupuli.yml

@@ -130,3 +130,5 @@ labels:
 teams_with_admin_access:
   - org-login: voxpupuli
     team-slug: project-maintainers
+  - org-login: voxpupuli
+    team-slug: tools/vox-pupuli-tasks