build(docker): avoid running command twice

Author: thomasleplus

pgp-verify-jar/Dockerfile

@@ -16,8 +16,7 @@ RUN apk -U upgrade \
     curl=8.14.1-r1 \
     git=2.49.1-r0 \
     gnupg=2.4.7-r0 \
-    && if apk -u list | grep -q -e . ; then \
-      apk -u list ; \
+    && if apk -u list | tee -a /dev/stderr | grep -q -e . ; then \
       exit 1 ; \
     fi \
     && apk cache clean \