fixup! try harder to only run tox unittest

.github/workflows/test.yml

@@ -17,12 +17,12 @@ jobs:
   # (like from pr#1942)
   unittests_as_user_smoke:
     name: "Smoke run: unittest as normal user on default runner"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     steps:
     - uses: actions/checkout@v4
     - uses: actions/setup-python@v5
+    - run: sudo apt install -y tox
     - name: "Run as user on default runer"
       run: |
-        sudo apt install -y tox
         # depsolve tests tend to be slow but are easy to parallize
-        tox -- test -n 16
+        tox -e py312 -- -n 16