github/workflows: install graphviz command line tool

.github/workflows/user_project_ci.yml

diff --git a/.github/workflows/user_project_ci.yml b/.github/workflows/user_project_ci.yml
index a4aee38..c7a1361 100644
--- a/.github/workflows/user_project_ci.yml
+++ b/.github/workflows/user_project_ci.yml
@@ -260,6 +260,7 @@
         key: ${{ runner.os }}-gds-${{ github.run_id }}
     - name: create synth svg
       run: |
+        sudo apt-get install -yq graphviz
         python -m pip install graphviz
         python << EOF
         import graphviz