api: disk: work around udev bug to ensure its database is updated

api: disk: work around udev bug to ensure its database is updated

There is a udev bug [0] which can ultimately lead to the udev database
for certain devices not being actively updated. Determining whether a
disk is used or not in get_disks() (in part) relies upon lsblk, which
queries the udev database. Ensure the information is updated by
manually calling 'udevadm trigger' for the changed devices.

It's most important for the 'directory' API path, as mounting depends
on the '/dev/disk/by-uuid'-symlink to be generated.

[0]: https://github.com/systemd/systemd/issues/18525

Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>