ci: Fix per-job build

.gitea/workflows/ci.yaml

@@ -33,6 +33,7 @@ jobs:
         run: |
           nix eval --json --apply "builtins.attrNames" .#ci.x86_64-linux | jq -cr '.[]' | while read job; do
             echo "Building $job"
+            nix build --no-link .#ci.x86_64-linux."$job" --json
             path="$(nix build --no-link .#ci.x86_64-linux."$job" --json | jq -r .[0].outputs.out)"
             echo "Caching $job"
             ci/push-to-cache.sh "$path"