ci(regression): test against MDAnalysis pre-release with eigh principal_axes

Author: harryswift01

.github/workflows/pr.yaml

@@ -89,6 +89,25 @@ jobs:
           python -m pip install --upgrade pip
           python -m pip install -e .[testing]
 
+      - name: Install MDA 2.11 pre-release
+        run: |
+          git clone https://github.com/MDAnalysis/mdanalysis.git "$RUNNER_TEMP/mdanalysis"
+          git -C "$RUNNER_TEMP/mdanalysis" checkout f765ecd77c8d51d79bec87c9780a0fab80c7d43c
+          python -m pip install "$RUNNER_TEMP/mdanalysis/package"
+
+      - name: Verify MDA uses eigh in principal_axes
+        run: |
+          python - <<'EOF'
+          import inspect
+          import MDAnalysis
+          from MDAnalysis.core import topologyattrs
+
+          print("MDAnalysis", MDAnalysis.__version__)
+          assert "np.linalg.eigh(atomgroup.moment_of_inertia" in inspect.getsource(
+              topologyattrs
+          )
+          EOF
+
       - name: Run fast regression tests
         run: |
           python -m pytest tests/regression \