Refresh mkdocs dependencies

Author: mdmintz

mkdocs_build/requirements.txt

@@ -20,7 +20,7 @@ lxml==5.2.1
 pyquery==2.0.0
 readtime==3.0.0
 mkdocs==1.6.0
-mkdocs-material==9.5.20
+mkdocs-material==9.5.21
 mkdocs-exclude-search==0.6.6
 mkdocs-simple-hooks==0.1.5
 mkdocs-material-extensions==1.3.1