add libegl1 dep to workflow

.github/workflows/docs.yml

         run: |
           sudo add-apt-repository --yes ppa:kicad/kicad-7.0-releases
           sudo apt update
-          sudo apt install -y --install-recommends kicad pipx libfuse2
+          sudo apt install -y --install-recommends kicad pipx libfuse2 libegl1
 
       - name: Install latest mdbook
         run: |