Use mermaid from mkdocs-material, not external plugin.

Dockerfile

@@ -6,7 +6,7 @@ SHELL ["/bin/bash", "-c"]
 # Base #
 ########
 
-RUN pip install mkdocs>=1.1.2 mkdocs-material>=7.1.0 mkdocs-mermaid2-plugin>=0.5.2
+RUN pip install mkdocs>=1.1.2 mkdocs-material>=7.1.0
 
 ##########
 # Linter #

doc.zih.tu-dresden.de/mkdocs.yml

@@ -189,7 +189,7 @@ markdown_extensions:
         custom_fences:
           - name: mermaid
             class: mermaid
-            format: !!python/name:mermaid2.fence_mermaid
+            format: !!python/name:pymdownx.superfences.fence_code_format
     - pymdownx.highlight
     - toc:
         permalink: True
@@ -198,9 +198,6 @@ markdown_extensions:
     - pymdownx.tabbed:
         alternate_style: True
 
-plugins:
-    - search
-    - mermaid2
           #  - mkdocs-video
 
 extra: