Manage the big stuff as early as possible

Chromium, Firefox, and xmonad (+ all the Haskell stuff) are the most
time consuming part of the Stage 1 build.  They are also a place where a
lot of build failures happen.  Let those failures happen as early as
possible so that retries get back to it more quickly.

Containerfile

@@ -23,7 +23,10 @@ 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
 
-# Configure the stage
+# Get the big stuff out of the way first
+RUN puppet agent --test --tags nest::role::workstation::chromium,nest::role::workstation::firefox,nest::role::workstation::xmonad --runtimeout 0; [ $? -eq 2 ]
+
+# Configure the rest of the stage
 RUN puppet agent --test --runtimeout 0; [ $? -eq 2 ]
 
 RUN rm -rf /var/db/repos