backport 2.2.4 staging for better 6.8 support

backport 2.2.4 staging for better 6.8 support

Use the current ZFS 2.2.4 staging tree [0] with commit deb7a8423 ("Fix
corruption caused by mmap flushing problems") on top.

Additionally, include an open, but ack'd, pull request [1] that avoids
a potential general protection fault due to touching a vbio after it
was handed off to the kernel.

[0]: https://github.com/openzfs/zfs/commits/zfs-2.2.4-staging/
[1]: https://github.com/openzfs/zfs/pull/16049

Both should mostly touch the module code.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>