Fix postgres12-client download

Dockerfile

@@ -16,7 +16,8 @@ RUN addgroup -g 4200 appgroup \
 # upgrade all installed packages to fix potential CVEs in advance
 # also remove apk package manager to hopefully remove dependecy on openssl 🤞
 RUN apk upgrade --no-cache --no-progress \
-  && apk add --no-cache --no-progress ca-certificates postgresql12-client postgresql15-client curl jq \
+  && apk add --no-cache --no-progress ca-certificates postgresql15-client curl jq \
+  && apk add --no-cache --no-progress --repository=https://dl-cdn.alpinelinux.org/alpine/v3.18/community postgresql12-client \
   && apk del --no-cache --no-progress apk-tools alpine-keys
 
 COPY --from=builder /pkg/ /usr/