embed build script version in its file; add zip-packages job to CI

.github/scripts/update-version.sh

@@ -0,0 +1,8 @@
+if [ ! -z $(git diff --name-only HEAD HEAD~1 | grep dependencies.gradle) ]; then
+  new_version="$(git log -n1 --format=format:"%H")"
+  sed --in-place "s!//version:.*!//version: $new_version!g" build.gradle
+  git add build.gradle
+  git commit -m "update buildscript version to $new_version"
+  git push
+  echo "[ci skip] update buildscript version"; 
+fi