fix(ci): extract appimagetool for FUSE-less containers

appimagetool is an AppImage itself and requires FUSE to self-mount.
CI containers typically don't have FUSE. Extract it with
--appimage-extract and run squashfs-root/AppRun instead.

package/rattler-build/linux/create_bundle.sh

@@ -59,6 +59,10 @@ sed -i "1s/.*/\nLIST OF PACKAGES:/" AppDir/packages.txt
 curl -LO https://github.com/AppImage/appimagetool/releases/download/continuous/appimagetool-$(uname -m).AppImage
 chmod a+x appimagetool-$(uname -m).AppImage
 
+# Extract appimagetool so it works in containers without FUSE
+./appimagetool-$(uname -m).AppImage --appimage-extract > /dev/null 2>&1
+APPIMAGETOOL=squashfs-root/AppRun
+
 if [ "${UPLOAD_RELEASE}" == "true" ]; then
     case "${BUILD_TAG}" in
         *weekly*)
@@ -76,7 +80,7 @@ fi
 echo -e "\nCreate the appimage"
 # export GPG_TTY=$(tty)
 chmod a+x ./AppDir/AppRun
-./appimagetool-$(uname -m).AppImage \
+${APPIMAGETOOL} \
   --comp zstd \
   --mksquashfs-opt -Xcompression-level \
   --mksquashfs-opt 22 \