Bump miniconf from 0.16.3 to 0.18.0

Bumps [miniconf](https://github.com/quartiq/miniconf) from 0.16.3 to 0.18.0.
- [Release notes](https://github.com/quartiq/miniconf/releases)
- [Changelog](https://github.com/quartiq/miniconf/blob/main/CHANGELOG.md)
- [Commits](quartiq/miniconf@v0.16.3...v0.18.0)

---
updated-dependencies:
- dependency-name: miniconf
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Cargo.toml

@@ -51,7 +51,7 @@ usbd-serial = "0.2.2"
 encdec = { version = "0.9", default-features = false }
 crc-any = { version = "2.5.0", default-features = false }
 panic-persist = { version = "0.3", features = ["custom-panic-handler", "utf8"] }
-miniconf = { version = "0.16", features = ["json-core", "derive", "postcard"]}
+miniconf = { version = "0.18", features = ["json-core", "derive", "postcard"]}
 miniconf_mqtt = "0.16"
 # Note: Keep `py/pyproject.toml` version in sync with the Minimq version used in FW.
 minimq = "0.9.0"