test controller docker container with bullseye instead of buster

controller/controller.Dockerfile

@@ -2,7 +2,7 @@ ARG GOLANG_VERSION=1.20.6
 ARG BUILDARGS
 ARG $GITLAB_PROXY
 
-FROM ${GITLAB_PROXY}golang:$GOLANG_VERSION-buster as builder
+FROM ${GITLAB_PROXY}golang:$GOLANG_VERSION-bullseye as builder
 WORKDIR /gosdn/
 COPY . .
 RUN --mount=type=cache,target=/root/go/pkg/mod \