Spring boot reproducible issue demonstration

to check if build is reproducible

Compare the hash manually

./gradlew -q clean jibBuildTar && md5sum user-backend/build/jib-image.tar \
&&./gradlew -q clean jibBuildTar && md5sum user-backend/build/jib-image.tar

if we use spring version 3.1.7 -> md5hash of tar is the same if we upgrade to 3.2.0 -> md5hash will be different