cgroup: bring list of delegated cgroup attributes up-to-date with current kernels

THis brings the list of attributes to delegate to managers of subcgroups
to the state of kernel 6.6.

We probably should unify this list, and maybe generate it automatically
from /sys/kernel/cgroup/delegate, but let's do that another time.

src/nspawn/nspawn-cgroup.c

@@ -35,6 +35,8 @@ static int chown_cgroup_path(const char *path, uid_t uid_shift) {
                        "cgroup.stat",
                        "cgroup.subtree_control",
                        "cgroup.threads",
+                       "memory.oom.group",
+                       "memory.reclaim",
                        "notify_on_release",
                        "tasks")
                 if (fchownat(fd, fn, uid_shift, uid_shift, 0) < 0)

src/shared/cgroup-setup.c

@@ -421,6 +421,8 @@ int cg_set_access(
                 { "cgroup.procs",           true  },
                 { "cgroup.subtree_control", true  },
                 { "cgroup.threads",         false },
+                { "memory.oom.group",       false },
+                { "memory.reclaim",         false },
                 {},
         };