Don't include master in the dashboard.

Because the dashboard data is collected in a totally different way, and
doesn't fit nicely here.

Author: nnethercote

site/src/request_handlers/dashboard.rs

@@ -71,9 +71,6 @@ pub async fn handle_dashboard(ctxt: Arc<SiteCtxt>) -> ServerResult<dashboard::Re
         versions
             .into_iter()
             .map(|v| ArtifactId::Tag(v.to_string()))
-            .chain(std::iter::once(
-                ctxt.index.load().commits().last().unwrap().clone().into(),
-            ))
             .collect::<Vec<_>>(),
     );