build(deps): bump serde from 1.0.208 to 1.0.209

Bumps [serde](https://github.com/serde-rs/serde) from 1.0.208 to 1.0.209.
- [Release notes](https://github.com/serde-rs/serde/releases)
- [Commits](serde-rs/serde@v1.0.208...v1.0.209)

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

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

Author: dependabot[bot]

Cargo.lock

@@ -27,7 +27,7 @@ js-sys = "0.3.69"
 mrml = { version = "4.0.1", features = ["parse", "render"], default-features = false }
 nom = { version = "7.1.3", features = ["alloc"] }
 pulldown-cmark = "0.9.2"
-serde = { version = "1.0.208", features = ["derive"] }
+serde = { version = "1.0.209", features = ["derive"] }
 serde-wasm-bindgen = "0.6.5"
 textwrap = "0.16.1"
 thiserror = "1.0.63"