workflows/manual-nixpkgs: Run the manual's tests

Author: nicoonoclaste

.github/workflows/manual-nixpkgs.yml

@@ -29,4 +29,4 @@ jobs:
           name: nixpkgs-ci
           signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
       - name: Building Nixpkgs manual
-        run: NIX_PATH=nixpkgs=$(pwd) nix-build --option restrict-eval true pkgs/top-level/release.nix -A manual
+        run: NIX_PATH=nixpkgs=$(pwd) nix-build --option restrict-eval true pkgs/top-level/release.nix -A manual -A manual.tests