fix: pin mkdocs<2.0 to prevent Material theme incompatibility

mkdocs 2.0 is incompatible with mkdocs-material 9.x. When installed
unpinned, pip now resolves to mkdocs 2.0 which causes the build to
produce broken HTML with a Jekyll meta tag instead of the Material theme.

Pinning mkdocs<2.0 ensures the docs site renders correctly with the
Material theme.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: eurunuela

.github/workflows/docs.yml

@@ -32,7 +32,7 @@ jobs:
           python-version: '3.x'
 
       - name: Install dependencies
-        run: pip install mkdocs-material
+        run: pip install mkdocs-material "mkdocs<2.0"
 
       - name: Build documentation
         run: mkdocs build --strict