.github/selftests: Make sure we install a numpy 1.* version for old m…

…atplotlib

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>

.github/workflows/selftests.yml

@@ -58,6 +58,7 @@ jobs:
       - name: Install dependencies
         run: |
           sudo apt-get install -y xvfb libxkbcommon-x11-0 libxcb-icccm4 libxcb-shape0 libxcb-image0 libxcb-keysyms1 libxcb-randr0 libxcb-render-util0 libxcb-xinerama0 libxcb-xinput0 libxcb-xfixes0
+          [[ "$MATPLOTLIB_VERSION" == "3.8" ]] || [[ "$MATPLOTLIB_VERSION" == "3.9" ]] || pip install "numpy<2."
           pip install setuptools QtPy ${PYQT} "matplotlib==${MATPLOTLIB_VERSION}.*"
       - name: Run tests
         uses: GabrielBB/xvfb-action@v1