Update toml requirement from 0.5 to 0.8 (Azure#150)

Updates the requirements on [toml](https://github.com/toml-rs/toml) to permit the latest version.
- [Commits](toml-rs/toml@toml_datetime-v0.5.0...toml-v0.8.19)

---
updated-dependencies:
- dependency-name: toml
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

libazureinit/Cargo.toml

@@ -20,7 +20,7 @@ nix = {version = "0.29.0", features = ["fs", "user"]}
 block-utils = "0.11.1"
 tracing = "0.1.40"
 fstab = "0.4.0"
-toml = "0.5"
+toml = "0.8"
 regex = "1"
 lazy_static = "1.4"
 tempfile = "3.3.0"