Refine addblob.sh to upload blobs to s3

See https://bosh.io/docs/release-blobs/#saving-blobs

currently failing with

creating bosh release: k3s-packages-1.24.17+k3s1.tgz
Building a release from directory '/github/workspace':
  - Constructing packages from directory:
      - Reading package from '/github/workspace/packages/k3s':
          Collecting package files:
            Missing files for pattern 'k3s/k3s'
      - Reading package from '/github/workspace/packages/k3s-images':
          Collecting package files:
            Missing files for pattern 'k3s-images/k3s-airgap-images-amd64.tar'
      - Reading package from '/github/workspace/packages/kubectl-k3s':
          Collecting package files:
            Missing files for pattern 'kubectl/kubectl'
Exit code 1

addblob.sh

@@ -13,6 +13,8 @@ function addBlobOnChecksumChange() {
   src_checksum=$(cat "${src}"  | sha256sum |  cut -d " " -f1)
   if [ "${blob_checksum}" != "sha256:${src_checksum}" ] || [ "$blob_object_id" = "null" ]; then
     bosh add-blob ${src} ${target}
+    # See https://bosh.io/docs/release-blobs/#saving-blobs
+    bosh upload-blobs
   else
     echo "skipping blob creation for ${target} with existing checksum: ${src_checksum}"
   fi