oci: WithDefaultUnixDevices(): remove tun/tap from the default devices

A container should not have access to tun/tap device, unless it is explicitly
specified in configuration.

This device was already removed from docker's default, and runc's default;

- opencontainers/runc@2ce40b6
- https://github.com/moby/moby//commit/9c4570a958df42d1ad19364b1a8da55b891d850a

Per the commit message in runc, this should also fix these messages;

> Apr 26 03:46:56 foo.bar systemd[1]: Couldn't stat device /dev/char/10:200: No such file or directory

coming from systemd on every container start, when the systemd cgroup driver
is used, and the system runs an old (< v240) version of systemd
(the message was presumably eliminated by [1]).

[1]: systemd/systemd@d5aecba

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

oci/spec_opts.go

@@ -1192,20 +1192,13 @@ func WithDefaultUnixDevices(_ context.Context, _ Client, _ *containers.Container
 			Allow:  true,
 		},
 		{
+			// "dev/ptmx"
 			Type:   "c",
 			Major:  intptr(5),
 			Minor:  intptr(2),
 			Access: rwm,
 			Allow:  true,
 		},
-		{
-			// tuntap
-			Type:   "c",
-			Major:  intptr(10),
-			Minor:  intptr(200),
-			Access: rwm,
-			Allow:  true,
-		},
 	}...)
 	return nil
 }