build(docker): avoid running command twice

Author: thomasleplus

latex/Dockerfile

@@ -34,9 +34,7 @@ RUN apt-get update \
     texlive-latex-extra=2024.20250309-2 \
     texlive-science=2024.20250309-2 \
     texlive=2024.20250309-1 \
-    && IFS=$'\n\t' \
-    && if apt-get -s upgrade | grep -q -e '^Inst ' ; then \
-      apt-get -s upgrade | grep -e '^Inst ' ; \
+    && if apt-get -s upgrade | tee -a /dev/stderr | grep -q -e '^Inst ' ; then \
       exit 1 ; \
     fi \
     # Removing documentation packages *after* installing them is kind of hacky,