revert changes on Dockerfiles

docker/DebugDockerfile

@@ -1,14 +1,8 @@
-FROM ubuntu:20.04
+FROM alpine
 LABEL maintainer="Team ACID @ Zalando <team-acid@zalando.de>"
 
 # We need root certificates to deal with teams api over https
-RUN apt-get update \
-    && apt-get install --no-install-recommends -y \
-        curl \
-        ca-certificates \
-        go \
-        git \
-        musl-dev
+RUN apk --no-cache add ca-certificates go git musl-dev
 
 COPY build/* /
 
@@ -22,4 +16,4 @@ RUN chown -R pgo:pgo /dlv
 USER pgo:pgo
 RUN ls -l /
 
-CMD ["/dlv", "--listen=:7777", "--headless=true", "--api-version=2", "exec", "/postgres-operator"]
+CMD ["/dlv", "--listen=:7777", "--headless=true", "--api-version=2", "exec", "/postgres-operator"]