Dolfinx ref

Author: schnellerhase

.github/workflows/dolfinx-tests.yml

@@ -60,7 +60,7 @@ jobs:
         with:
           path: ./dolfinx
           repository: FEniCS/dolfinx
-          ref: main
+          ref: schnellerhase/nanobind-broken
       - name: Get DOLFINx
         if: github.event_name == 'workflow_dispatch'
         uses: actions/checkout@v5