switch to harbor for ubi8-rust-builder (#352)

Author: Maleware

template/docker/Dockerfile.j2

@@ -2,7 +2,7 @@
 # This file is automatically generated from the templates in stackabletech/operator-templating
 # DON'T MANUALLY EDIT THIS FILE
 # =============
-FROM docker.stackable.tech/stackable/ubi8-rust-builder AS builder
+FROM oci.stackable.tech/sdp/ubi8-rust-builder AS builder
 
 FROM registry.access.redhat.com/ubi8/ubi-minimal AS operator