Move to unified build script

.github/scripts/update-version.sh

@@ -0,0 +1,10 @@
+if [ ! -z $(git diff --name-only HEAD HEAD~1 | grep build.gradle) ]; then
+  new_version="$(git log -n1 --format=format:"%H")"
+  sed --in-place "s!^//version:.*!//version: $new_version!g" build.gradle
+  git add build.gradle
+  git commit -m "[ci skip] update build script version to $new_version"
+  git push
+  echo "Updated buildscript version to $new_version"; 
+else
+  echo "Ignored buildscript version update: no changes detected"
+fi