[UPD] hoist jinja2 ahead of systemd

systemd generates source from jinja2 templates, and the Python set sits at the
end of packages.sh while systemd is in the middle. The list order is the runtime
closure, not the build order -- so the packages that must exist before another
one builds are named in STAGE2_FIRST rather than moved.

--- FR ---

systemd genere du code depuis des gabarits jinja2, et l ensemble Python figure en
fin de packages.sh quand systemd est au milieu. L ordre de la liste est la
fermeture d execution, pas celle de construction : les paquets qui doivent
exister avant qu un autre se batisse sont nommes dans STAGE2_FIRST plutot que
deplaces.

Assisted-by: Claude Opus 5

scripts/build-stage2.sh

@@ -718,7 +718,7 @@ NOTE
 STAGE2_FIRST=(texinfo libxml2 binutils pkgconf wget libxslt
               python-packaging python-pyproject-hooks python-build
               python-installer python-setuptools python-wheel
-              python-setuptools-scm)
+              python-setuptools-scm python-markupsafe python-jinja)
 
 # Packages the chroot needs that can only come from repo2.
 #
@@ -779,6 +779,7 @@ CHROOT_STAGE2_PKGS=(
     python-packaging python-pyproject-hooks python-build
     python-installer python-setuptools python-wheel
     python-setuptools-scm
+    python-markupsafe python-jinja
 )
 
 # Packages whose sources must be extracted on the HOST, because the chroot