Update Rust crate toml to 0.9.4 (#334)

Co-authored-by: oxide-renovate[bot] <146848827+oxide-renovate[bot]@users.noreply.github.com>

Author: oxide-renovate[bot]

Cargo.lock

@@ -80,7 +80,7 @@ tap = "1.0.1"
 textwrap = "0.16.2"
 thiserror = "2"
 tokio = "1.47.0"
-toml = "0.9.3"
+toml = "0.9.4"
 tracing = "0.1.41"
 tracing-appender = "0.2.3"
 tracing-slog = { git = "https://github.com/oxidecomputer/tracing-slog", default-features = false }