Remove /var/tmp/portage to hopefully reset distcc

Otherwise, somehow a state file gets set up owned by root and Portage,
notably Chromium, fails to use distcc.

Containerfile

@@ -22,13 +22,7 @@ RUN eselect profile set "nest:${PROFILE}"
 RUN emerge --info
 RUN USE='-vaapi' emerge -v --update --deep --newuse --with-bdeps=y @world
 RUN emerge -v --update --deep --newuse --with-bdeps=y @world
-RUN emerge --depclean
-
-# Debugging
-RUN puppet agent --test --tags nest::lib::repo; [ $? -eq 2 ]
-RUN locale
-RUN find /var/tmp/portage -ls
-RUN emerge -pv x11-misc/taffybar
+RUN emerge --depclean && rm -rf /var/tmp/portage
 
 # Configure the stage
 RUN puppet agent --test --runtimeout 0; [ $? -eq 2 ]