build: run OS pkg update on image build

Author: sbocinec

Dockerfile

@@ -32,7 +32,8 @@ 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
+    && chmod o+rx /app/kminion \
+    && apk upgrade --no-cache
 USER redpanda
 
 ENTRYPOINT ["/app/kminion"]