linux: fix appimage (#731)

* always use latest version of pkg2appimage

* generate zsync file to make the appimage updateable

* install fuse for GH actions

* remove fuse

* run AppImage

* comment converts

* getting info on images

* using bugfix from #536

* add DOCKER_BUILD flag

* extract AppImageAssistant before running it

* use local `convert` and not from `pkg2appimage`

create_appimage.sh

@@ -1,9 +1,19 @@
 #!/bin/bash
+
+cd ..
+
 if [[ "$VSCODE_ARCH" == "x64" ]]; then
   # install a dep needed for this process
   sudo apt-get install desktop-file-utils
 
-  cd ..
-  export DOCKER_BUILD=1
-  bash -e src/resources/linux/appimage/pkg2appimage VSCodium-AppImage-Recipe.yml
+  wget -c https://github.com/$(wget -q https://github.com/AppImage/pkg2appimage/releases -O - | grep "pkg2appimage-.*-x86_64.AppImage" | head -n 1 | cut -d '"' -f 2)
+  chmod +x ./pkg2appimage-*.AppImage
+
+  ./pkg2appimage-*.AppImage --appimage-extract && mv ./squashfs-root ./pkg2appimage.AppDir
+  
+  sed -i 's/generate_type2_appimage/generate_type2_appimage -u "gh-releases-zsync|VSCodium|vscodium|latest|*.AppImage.zsync"/' pkg2appimage.AppDir/AppRun
+
+  bash -ex pkg2appimage.AppDir/AppRun VSCodium-AppImage-Recipe.yml
 fi
+
+cd vscode