Comment out colcon clean from setup

to avoid unintentional removal of built packages
from the persistent overlay workspace volume.
Users can uncomment the line locally
or simply remove the overlay workspace volume
if they want to rebuild packages from scratch.

.devcontainer/update-content-command.sh

@@ -49,9 +49,9 @@ then
 fi
 echo BUILD_PACKAGES: $BUILD_PACKAGES
 
-colcon clean packages --yes \
-    --packages-select ${BUILD_PACKAGES} \
-    --base-select install
+# colcon clean packages --yes \
+#     --packages-select ${BUILD_PACKAGES} \
+#     --base-select install
 
 . $UNDERLAY_WS/install/setup.sh
 colcon build \