ci: added graphviz to deps

Author: ErikBjare

.github/workflows/build.yml

@@ -20,7 +20,7 @@ jobs:
         python-version: 3.12
     - name: Install APT dependencies
       run: |
-        sudo apt-get install -y git build-essential apt-utils wget libfreetype6 libpng-dev libopenblas-dev gcc gfortran libsnappy-dev
+        sudo apt-get install -y git build-essential apt-utils wget libfreetype6 libpng-dev libopenblas-dev gcc gfortran libsnappy-dev graphviz
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip poetry