ci/eval: move flake eval check to eval-aliases job

Author: cole-h

.github/workflows/eval.yml

@@ -47,9 +47,6 @@ jobs:
         with:
           extra_nix_config: sandbox = true
 
-      - name: Ensure flake outputs on all systems still evaluate
-        run: nix --experimental-features 'nix-command flakes' flake check --all-systems --no-build
-
       - name: Evaluate the list of all attributes and get the systems matrix
         id: systems
         run: |
@@ -78,6 +75,9 @@ jobs:
         with:
           extra_nix_config: sandbox = true
 
+      - name: Ensure flake outputs on all systems still evaluate
+        run: nix --experimental-features 'nix-command flakes' flake check --all-systems --no-build
+
       - name: Query nixpkgs with aliases enabled to check for basic syntax errors
         run: |
           time nix-env -I ./nixpkgs -f ./nixpkgs -qa '*' --option restrict-eval true --option allow-import-from-derivation false >/dev/null