try to build graphviz 13.x again

Author: songmeo

.readthedocs.yml

@@ -7,7 +7,16 @@ build:
   tools:
     python: "3.10"
   apt_packages:
-    - graphviz
+    - build-essential
+    - libsodium-dev
+    - libargon2-dev
+  jobs:
+    pre_create_environment:
+    - wget https://gitlab.com/api/v4/projects/4207231/packages/generic/graphviz-releases/13.1.0/graphviz-13.1.0.tar.gz
+    - tar xzf graphviz-13.1.0.tar.gz
+    - cd ./graphviz-13.1.0 && ./configure -prefix=$HOME/.graphviz --disable-perl --disable-python --disable-go --disable-java --disable-lua --disable-tcl && make install
+    - ln -sf $PWD/graphviz/13.1.0/bin/dot /usr/local/bin/dot
+    - dot -V
 
 sphinx:
   configuration: docs/conf.py

docs/static/custom.css

@@ -1,12 +1,3 @@
-/* See https://github.com/OpenCyphal/pycyphal/issues/321 */
-object.inheritance, img.inheritance {
-    max-width: 25%;
-    width: 25%;
-    height: auto;
-    display: block;
-    margin: auto;
-}
-
 /* Gray text is ugly. Text should be black. */
 body {
     color: #000;