Update packages before rebuilding everything

ncurses is failing to compile.  It may be too much to ask to rebuild and
update everything in one step.

Containerfile

@@ -17,6 +17,7 @@ COPY --from=nest-overlay / /var/db/repos/nest/
 # Rebuild all packages using a custom profile
 RUN eselect profile set "nest:${PROFILE}"
 RUN emerge --info && emerge -v1 portage
+RUN emerge --info && emerge -vDuN --with-bdeps=y @world
 RUN emerge --info && emerge -ev @world
 RUN emerge --depclean