Bump toml from 0.8.14 to 0.8.15 (#755)

Bumps [toml](https://github.com/toml-rs/toml) from 0.8.14 to 0.8.15.
- [Commits](toml-rs/toml@toml-v0.8.14...toml-v0.8.15)

---
updated-dependencies:
- dependency-name: toml
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Cargo.lock

@@ -56,7 +56,7 @@ tempfile = "3.10.1"
 test-common = { path = "test-common" }
 thouart = { git = "https://github.com/oxidecomputer/thouart.git" }
 tokio = { version = "1.38.0", features = ["full"] }
-toml = "0.8.14"
+toml = "0.8.15"
 toml_edit = "0.22.15"
 url = "2.5.2"
 uuid = { version = "1.9.1", features = ["serde", "v4"] }