return env, but change from vfs to overlay2

.github/workflows/build.yml

@@ -36,6 +36,10 @@ jobs:
       
       # the build is fully handled by the reusable github action
       - name: Build Custom Image
+        env:
+          _BUILDAH_STARTED_IN_USERNS: ""
+          BUILDAH_ISOLATION: chroot
+          STORAGE_DRIVER: overlay2
         uses: blue-build/github-action@v1.8
         with:
           recipe: ${{ matrix.recipe }}