Remove more docs

.github/Dockerfile

@@ -13,7 +13,7 @@ WORKDIR /sage
 RUN LC_ALL=C find local src pkgs -type f -exec strip '{}' ';' 2>&1 | grep -v "file format not recognized" || true
 
 # To exclude doc directory in the next stage
-RUN rm -rf local/share/doc
+RUN rm -rf local/share/doc local/share/*/doc local/share/*/examples local/share/singular/html
 
 FROM ghcr.io/sagemath/sage/sage-ubuntu-jammy-minimal-with-system-packages:latest