chore: Reorganize files into folders

to make it plain where each file belongs in the containers file system
and to simplify the `ADD` directives in the Containerfile.

Signed-off-by: Andreas Hartmann <hartan@7x.de>

Containerfile

@@ -16,13 +16,11 @@
 
 FROM quay.io/centos/centos:stream9
 
-ADD /setup.sh /xpackages.txt /root/
+ADD /root/ /root/
-ADD /containers.conf /home/podman/.config/containers/containers.conf
+ADD /etc/ /etc/
-ADD /podman.service /podman.socket /prune.service /prune.timer /home/podman/.config/systemd/user/
+ADD /home/ /home/
-ADD /runner.service /home/runner/.config/systemd/user/
-ADD kmsglog.conf /etc/systemd/system.conf.d/
 
-# Allow image-builders to choose another version becides "latest" should
+# Allow image-builders to choose another version besides "latest" should
 # an incompatible change be introduced.
 ARG RUNNER_VERSION=latest