rootless: fix "stat /run/user/1000: no such file or directory" on `kubectl run`
rootless: fix "stat /run/user/1000: no such file or directory" on `kubectl run`

k3s was mounting a tmpfs on `/run` by itself, so it was hiding RootlessKit's `/run`.

Signed-off-by: Akihiro Suda <10ddef0dea2a66ab193b07198faa879adcb213d8@hco.ntt.co.jp>

rancher/k3s,rancher/k3s