also cache index.crates.io

This is used by the rust tests

.github/workflows/ci.yaml

@@ -301,7 +301,7 @@ jobs:
       - name: Add /etc/host entries
         run: |
           # precache dns entries to avoid timeouts in the runs later
-          for host in updates.suse.com registry.suse.com registry.opensuse.org; do
+          for host in index.crates.io updates.suse.com registry.suse.com registry.opensuse.org; do
             echo -e "$(getent ahostsv4 $host | grep STREAM | cut -d' ' -f1 | head -n 1)\t$host"  | sudo tee -a /etc/hosts
           done