[CI] (Purity): require both P0.5 closure probes now that the headers exist

- the ctest and the include-graph-check job pass --require-all, so a SKIP on
  MGPipeValueTypes.h or ProgramArtifacts.h is red from here on

.github/workflows/test.yml

@@ -346,7 +346,7 @@ jobs:
         run: sudo apt-get update && sudo apt-get install -y clang-20
 
       - name: Include-closure assertions and negative control
-        run: python3 scripts/check_include_closure.py --mode both --compiler clang++-20 --self-test
+        run: python3 scripts/check_include_closure.py --mode both --compiler clang++-20 --self-test --require-all
 
   benchmark:
     runs-on: ubuntu-latest