vendor: bump runc to rc94

One notable change is cgroup manager's Set now accept Resources rather
than Cgroup (see https://github.com/opencontainers/runc/pull/2906).
Modify the code accordingly.

Also update runc dependencies (as hinted by hack/lint-depdendencies.sh):

	github.com/cilium/ebpf v0.5.0
	github.com/containerd/console v1.0.2
	github.com/coreos/go-systemd/v22 v22.3.1
	github.com/godbus/dbus/v5 v5.0.4
	github.com/moby/sys/mountinfo v0.4.1
	golang.org/x/sys v0.0.0-20210426230700-d19ff857e887
	github.com/google/go-cmp v0.5.4
	github.com/kr/pretty v0.2.1
	github.com/opencontainers/runtime-spec v1.0.3-0.20210326190908-1c3f411f0417

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

vendor/github.com/opencontainers/runc/libcontainer/userns/userns_linux.go

@@ -0,0 +1,37 @@
+package userns
+
+import (
+	"sync"
+
+	"github.com/opencontainers/runc/libcontainer/user"
+)
+
+var (
+	inUserNS bool
+	nsOnce   sync.Once
+)
+
+// runningInUserNS detects whether we are currently running in a user namespace.
+// Originally copied from github.com/lxc/lxd/shared/util.go
+func runningInUserNS() bool {
+	nsOnce.Do(func() {
+		uidmap, err := user.CurrentProcessUIDMap()
+		if err != nil {
+			// This kernel-provided file only exists if user namespaces are supported
+			return
+		}
+		inUserNS = uidMapInUserNS(uidmap)
+	})
+	return inUserNS
+}
+
+func uidMapInUserNS(uidmap []user.IDMap) bool {
+	/*
+	 * We assume we are in the initial user namespace if we have a full
+	 * range - 4294967295 uids starting at uid 0.
+	 */
+	if len(uidmap) == 1 && uidmap[0].ID == 0 && uidmap[0].ParentID == 0 && uidmap[0].Count == 4294967295 {
+		return false
+	}
+	return true
+}