vendor: update to the latest systemd_ctypes

We didn't sync this in a while and there have been a lot of changes.

We also have a critical bug fix included: we recently introduced a test
case (in 0bb7438820) which triggers a
segfault in the binding layer of systemd_ctypes due to FFI call
trampolines being garbage collected while they're still running.

This is currently blocking downstream packaging on several non-x86_64
architectures.

src/cockpit/channels/filesystem.py

@@ -31,6 +31,7 @@ from typing import Callable, Iterable
 
 from cockpit._vendor.systemd_ctypes import Handle, PathWatch
 from cockpit._vendor.systemd_ctypes.inotify import Event as InotifyEvent
+from cockpit._vendor.systemd_ctypes.pathwatch import Listener as PathWatchListener
 
 from ..channel import Channel, ChannelError, GeneratorChannel
 from ..jsonutil import (
@@ -298,7 +299,7 @@ class Follow(enum.Enum):
     YES = True
 
 
-class FsInfoChannel(Channel):
+class FsInfoChannel(Channel, PathWatchListener):
     payload = 'fsinfo'
 
     # Options (all get set in `do_open()`)

vendor/systemd_ctypes

@@ -1 +1 @@
-Subproject commit 46c18b5783f674e28fe2fab17e4a691b0762bbf4
+Subproject commit 833f5cee8ea5d4c93aecf0ac2bf517cd5b52f5ec