build: Bump zbus from 3.15.2 to 4.1.2

Bumps [zbus](https://github.com/dbus2/zbus) from 3.15.2 to 4.1.2.
- [Release notes](https://github.com/dbus2/zbus/releases)
- [Commits](https://github.com/dbus2/zbus/compare/zbus-3.15.2...zbus-4.1.2)

---
updated-dependencies:
- dependency-name: zbus
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.toml

@@ -48,7 +48,7 @@ tracer = { path = "tracer" }
 vm-memory = "0.14.1"
 vmm = { path = "vmm" }
 vmm-sys-util = "0.12.1"
-zbus = { version = "3.15.2", optional = true }
+zbus = { version = "4.1.2", optional = true }
 
 [dev-dependencies]
 dirs = "5.0.1"