Bump to runc main

By using main instead of the v1.1 branch, we drop an unnecessary
dependency on cilium/ebpf, saving ~1mb of binary size.

Signed-off-by: Matt Heon <mheon@redhat.com>

vendor/github.com/opencontainers/runc/libcontainer/cgroups/fs2/defaultpath.go

@@ -55,6 +55,9 @@ func _defaultDirPath(root, cgPath, cgParent, cgName string) (string, error) {
 		return filepath.Join(root, innerPath), nil
 	}
 
+	// we don't need to use /proc/thread-self here because runc always runs
+	// with every thread in the same cgroup. This lets us avoid having to do
+	// runtime.LockOSThread.
 	ownCgroup, err := parseCgroupFile("/proc/self/cgroup")
 	if err != nil {
 		return "", err