Removes duplicate mermaid tag

templates/partials/header.html

@@ -9,9 +9,6 @@
       mermaid.initialize({ startOnLoad: true });
     </script>
 
-    <script src="https://cdn.jsdelivr.net/npm/mermaid/dist/mermaid.min.js"></script>
-    <script>mermaid.initialize({startOnLoad:true});</script>
-
     {# Site title #}
     {% set current_path = current_path | default(value="/") %}
     {% if current_path == "/" %}