Vagrantfile.fedora: exclude systemd from upgrade

A bug in systemd-249.6-2.fc35.x86_64 prevents rootless containers from
start when systemd manager is used.

Apparently, "config exclude" is not working in F35 dnf shell either, so
use a workaround of specifying --exclude from the command line.

This should fix runc CI for the time being.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Vagrantfile.fedora

@@ -17,8 +17,14 @@ Vagrant.configure("2") do |config|
     # Work around dnf mirror failures by retrying a few times
     for i in $(seq 0 2); do
       sleep $i
-      cat << EOF | dnf -y shell && break
-config exclude kernel,kernel-core
+      # 1. "config exclude" dnf shell command is not working in Fedora 35
+      # (see https://bugzilla.redhat.com/show_bug.cgi?id=2022571);
+      # the workaround is to specify it as an option.
+      # 2. systemd 249.6-2.fc35 has a bug preventing rootless containers
+      # from starting when --systemd-cgroup is used for runc run
+      # (see https://bugzilla.redhat.com/show_bug.cgi?id=2022041),
+      # the workaround is not to upgrade systemd.
+      cat << EOF | dnf -y --exclude=kernel,kernel-core,systemd,systemd-* shell && break
 config install_weak_deps false
 update
 install iptables gcc make golang-go glibc-static libseccomp-devel bats jq git-core criu