Separately update zbus to 1.9.2 to fix cargo audit issue

[rnestler]

This was done using cargo update zbus --precise=1.9.2, since cargo update did only update to 1.9.1.

Also note that now runing cargo update will downgrade zbus again to 1.9.1:

% cargo update
Updating crates.io index
Updating bitflags v1.2.1 -> v1.3.2
  Adding cfg-if v0.1.10
Removing memoffset v0.6.4
Updating nix v0.20.2 -> v0.17.0
  Adding void v1.0.2
Updating zbus v1.9.2 -> v1.9.1
Updating zbus_macros v1.9.2 -> v1.9.1

See also the following cargo issues:

• cargo update silently doesn't update tokio-threadpool without --precise rust-lang/cargo#7671
• dependency downgrade on cargo update rust-lang/cargo#5702

The reason for this is that cargo audit complained about a vulnerability (https://github.com/rnestler/reboot-arch-btw/runs/3869525660):

Run cargo audit
   Fetching advisory database from `https://github.com/RustSec/advisory-db.git`
     Loaded 367 security advisories (from /github/home/.cargo/advisory-db)
   Updating crates.io index
   Scanning Cargo.lock for vulnerabilities (116 crate dependencies)
error: 1 vulnerability found!
Crate:         nix
Version:       0.17.0
Title:         Out-of-bounds write in nix::unistd::getgrouplist
Date:          2021-09-27
ID:            RUSTSEC-2021-0119
URL:           https://rustsec.org/advisories/RUSTSEC-2021-0119
Solution:      Upgrade to ^0.20.2 OR ^0.21.2 OR ^0.22.2 OR >=0.23.0
Dependency tree: 
nix 0.17.0
└── zbus 1.9.1
   └── notify-rust 4.5.4
       └── reboot-arch-btw 0.3.2