common: bump pve-rs dep to 0.8.5 for Proxmox::RS::Notify

common: bump pve-rs dep to 0.8.5 for Proxmox::RS::Notify

Note: this is more of a soft requirement, since as long as the Notify
module isn't loaded we don't need the latest version.
This is important to keep in mind since we do not currently have a
`pmg-rs` notify `Context` implementation and thus cannot depend on a
newer `pmg-rs`. However, as long as pmg code doesn't try to *use* the
Notify module, this won't be a problem.

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>