ci: remove platforms without graphviz

.github/workflows/ci.yml

@@ -60,13 +60,13 @@ jobs:
       matrix:
         os: [ ubuntu-latest ]
         python-version: ["3.10", "3.12"]
-        include:
-          - os: macos-latest
-            python-version: "3.9"
-          - os: windows-latest
-            python-version: "3.9"
-          - os: macos-14  # Apple silicon runner
-            python-version: '3.12'
+#        include:  # todo: activate when we can install graphviz on these platforms
+#          - os: macos-latest
+#            python-version: "3.9"
+#          - os: windows-latest
+#            python-version: "3.9"
+#          - os: macos-14  # Apple silicon runner
+#            python-version: '3.12'
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
@@ -79,6 +79,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
+          sudo apt install graphviz -y
           pip install -e .[dev]
       - name: Download test data
         run: python data/download_test_files.py > /dev/null