Merge pull request #10583 from mhilbrunner/gh-2404-imagemagick

GH: Offline builds need to install imagemagick on Ubuntu 24.04+

.github/workflows/build_offline_docs.yml

@@ -47,7 +47,7 @@ jobs:
           echo "$VIRTUAL_ENV/bin" >> $GITHUB_PATH
           echo "VIRTUAL_ENV=$VIRTUAL_ENV" >> $GITHUB_ENV
           sudo apt update
-          sudo apt install parallel libwebp7
+          sudo apt install parallel libwebp7 imagemagick
 
       - name: Save virtualenv cache
         uses: actions/cache/save@v4