Add user to docker image to avoid running as root

Author: simon0191

Dockerfile

@@ -30,5 +30,9 @@ RUN CGO_ENABLED=0 go build \
 FROM alpine:3.17
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 COPY --from=builder /app/bin/kminion /app/kminion
+RUN addgroup -S redpanda \
+    && adduser -S redpanda -G redpanda \
+    && chmod o+rx /app/kminion
+USER redpanda
 
 ENTRYPOINT ["/app/kminion"]