Bump github.com/opencontainers/runc from 1.0.0-rc93 to 1.0.0-rc94

Bumps [github.com/opencontainers/runc](https://github.com/opencontainers/runc) from 1.0.0-rc93 to 1.0.0-rc94.
- [Release notes](https://github.com/opencontainers/runc/releases)
- [Commits](https://github.com/opencontainers/runc/compare/v1.0.0-rc93...v1.0.0-rc94)

Signed-off-by: dependabot[bot] <support@github.com>

vendor/github.com/opencontainers/runc/libcontainer/system/linux.go

@@ -3,12 +3,9 @@
 package system
 
 import (
-	"os"
 	"os/exec"
-	"sync"
 	"unsafe"
 
-	"github.com/opencontainers/runc/libcontainer/user"
 	"golang.org/x/sys/unix"
 )
 
@@ -87,52 +84,6 @@ func Setctty() error {
 	return nil
 }
 
-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
-}
-
-// GetParentNSeuid returns the euid within the parent user namespace
-func GetParentNSeuid() int64 {
-	euid := int64(os.Geteuid())
-	uidmap, err := user.CurrentProcessUIDMap()
-	if err != nil {
-		// This kernel-provided file only exists if user namespaces are supported
-		return euid
-	}
-	for _, um := range uidmap {
-		if um.ID <= euid && euid <= um.ID+um.Count-1 {
-			return um.ParentID + euid - um.ID
-		}
-	}
-	return euid
-}
-
 // SetSubreaper sets the value i as the subreaper setting for the calling process
 func SetSubreaper(i int) error {
 	return unix.Prctl(unix.PR_SET_CHILD_SUBREAPER, uintptr(i), 0, 0, 0)