fix: pull postgresql18-client from edge instead of docker image (#25)

Reviewed-on: #25
Co-authored-by: Timo Behrendt <t.behrendt@t00n.de>
Co-committed-by: Timo Behrendt <t.behrendt@t00n.de>

Dockerfile

@@ -1,15 +1,15 @@
-FROM docker.io/postgres:18.1@sha256:28bda6d50590658221007b10573830c941b483e9d1a5bc2713a3f60477df8389 AS postgresql
-
 FROM docker.io/alpine:3.22@sha256:4b7ce07002c69e8f3d704a9c5d6fd3053be500b7f1c69fc0d80990c2ad8dd412 AS base
 
-COPY --from=postgresql /usr/bin/pg_dump /usr/local/bin/pg_dump
-COPY --from=postgresql /usr/bin/psql /usr/local/bin/psql
+# Add edge repository for postgresql18-client
+RUN echo '@edge http://dl-cdn.alpinelinux.org/alpine/edge/main' >> /etc/apk/repositories
 
 RUN apk update && apk add --no-cache \
     bash \
     curl \
     restic \
-    jq
+    jq \
+    postgresql18-client@edge \
+    libpq@edge
 
 WORKDIR /app