Incorrect permissions are set for x11SockDir

[GrosQuildu]

The OpenNewXServerListener methods creates x11SockDir directory with 1777 permissions, instead of 0o1777 - it is decimal vs octal problem. The permissions that are now set are 1777 = 0o3361.

teleport/lib/sshutils/x11/conn.go

Lines 76 to 79 in 9099591

	// Create /tmp/.X11-unix if it doesn't exist (such as in CI)
	if err := os.Mkdir(x11SockDir(), 1777); err != nil && !errors.Is(err, os.ErrExist) {
	return nil, Display{}, trace.Wrap(err)
	}

Moreover, the StickyBit should be set with the os.ModeSticky to work on all platforms. E.g., the 0o1777 won't set the StickyBit on OSX.