fix system image library uninstallation on macos x86 (#7622)

Author: pmeier

.github/scripts/setup-env.sh

@@ -27,9 +27,8 @@ if [[ "${OS_TYPE}" == "macos" && $(uname -m) == x86_64 ]]; then
   # The x86 macOS runners, e.g. the GitHub Actions native "macos-12" runner, has some JPEG and PNG libraries
   # installed by default that interfere with our build. We uninstall them here and use the one from conda below.
   IMAGE_LIBS=$(brew list | grep -E "jpeg|png")
-  echo "${IMAGE_LIBS}"
-  for lib in "${IMAGE_LIBS}"; do
-    brew uninstall --ignore-dependencies --force "${lib}" || true
+  for lib in $IMAGE_LIBS; do
+    brew uninstall --ignore-dependencies --force "${lib}"
   done
   echo '::endgroup::'
 fi